Company lists · Data refreshed September 2026

Top 25 Professional services firms based in Ottawa, Canada

Name: Professional services firms based in Ottawa, Canada
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 5, 2026 80 companies tracked

RevenueBase identified 80 company matches for professional services firms associated with Ottawa, Canada as of September 2026 and tracks 1,275 professional contacts across them, including 633 with verified work emails. Across Canada, Toronto is the largest hub for this category (348 companies); Ottawa has 80.

This list covers company matches for professional services firms associated with Ottawa, Canada, found by RevenueBase SmartSearch using the meaning of business descriptions in its company graph at Exact. Ranked by professionals tracked, largest first. Rows show recorded descriptions where available, Exact search membership and the snapshot date. Data refreshed September 5, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase SmartSearch, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list RevenueBase SmartSearch · Exact Recorded Sep 5, 2026 How this list was built

80Companies

1,275Contacts tracked

633Verified emails

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The 25 largest professional services firms based in Ottawa, Canada

Ranked by team size

Top 25 of 80 company matches for professional services firms based in Ottawa, Canada, ordered by professional contacts tracked in RevenueBase, largest first. Recorded Sep 5, 2026. The RevenueBase SmartSearch column shows Exact match membership in this saved search. Click a contact count to view that company's people. Totals use company locations recorded by RevenueBase; the displayed preview is a smaller selection.
#	Company	RevenueBase SmartSearch	Headquarters	Employees	Contacts
1	Welch LLP	Exact match	Ottawa, ON, CanadaHQ recorded Sep 5, 2026	201-500	399 contacts →
	Exact match “Welch LLP is a Chartered Public Accounting firm that has deep roots in the communities it serves.” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
2	Marcil Lavallée	Exact match	Ottawa, ON, CanadaHQ recorded Sep 5, 2026	51-200	109 contacts →
	Exact match “Marcil Lavallée est un partenaire engagé qui contribue activement à la réussite de ses clients en anticipant leurs besoins et en leur offrant une gamme complète de solutions…” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
3	Ggfl LLP	Exact match	Ottawa, ON, CanadaHQ recorded Sep 5, 2026	51-200	94 contacts →
	Exact match “GGFL is the tax planning and accounting firm for Ottawa’s successful business people.” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
4	Logan Katz LLP	Exact match	Ottawa, ON, CanadaHQ recorded Sep 5, 2026	51-200	80 contacts →
	Exact match “Logan Katz is a forward-thinking public accounting firm delivering high-quality, client inspired accounting, taxation, assurance and business advisory services in Ottawa and…” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
5	Baker Tilly Ottawa LLP	Exact match	Ottawa, ON, CanadaHQ recorded Sep 5, 2026	51-200	80 contacts →
	Exact match “At Baker Tilly Ottawa LLP, we provide expert tax, assurance, and entrepreneurial services to help your business grow and prosper.” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
6	Mccay Duff LLP	Exact match	Ottawa, ON, CanadaHQ recorded Sep 5, 2026	51-200	66 contacts →
	Exact match “McCay Duff LLP is a full-service Chartered Accountants Firm that has been serving the Ottawa area since 1946.” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
7	LOW Murchison Radnoff LLP	Exact match	Ottawa, ON, CanadaHQ recorded Sep 5, 2026	51-200	52 contacts →
	Exact match “At Low Murchison Radnoff LLP we provide a full range of legal services to our clients.” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
8	TAAG	Exact match	Ottawa, ON, CanadaHQ recorded Sep 5, 2026	51-200	39 contacts →
	Exact match “Accounting + Tax • Law • Wealth Family Office • Marketing + Design” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
9	49 Solutions	Exact match	Ottawa, ON, CanadaHQ recorded Sep 5, 2026	11-50	19 contacts →
	Exact match “At 49 Solutions we consistently deliver top quality consulting services, supporting both business and technology.” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
10	Nīewe Consulting LTD	Exact match	Ottawa, ON, CanadaHQ recorded Sep 5, 2026	11-50	15 contacts →
	Exact match “Founded in 2004, Nīewe Consulting (formerly Baiame Consulting) is a majority women-owned and led professional services firm that does consulting differently.” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
11	AI TAX Consultants	Exact match	Ottawa, ON, CanadaHQ recorded Sep 5, 2026	11-50	13 contacts →
	Exact match “AI Tax Consultants specializes in delivering tax and accounting services to individuals, self-employed and corporations.” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
12	Hendry Warren LLP	Exact match	Ottawa, ON, CanadaHQ recorded Sep 5, 2026	51-200	12 contacts →
	Exact match “At Hendry Warren LLP our mission is to provide relevant, reliable information and advice to help our clients achieve their business goals, and offer superior client service in a…” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
13	Vaive And Associates Professional Corporation	Exact match	Ottawa, ON, CanadaHQ recorded Sep 5, 2026	11-50	8 contacts →
	Exact match “Vaive and Associates Professional Corporation is a tax consulting, business advisory and accounting firm.” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
14	Armstrong Jones LLP	Exact match	Ottawa, ON, CanadaHQ recorded Sep 5, 2026	1-10	8 contacts →
	Exact match “Armstrong Jones LLP is an accounting firm based in Ottawa, Ontario that offers services in accounting, audit and assurance, tax planning and compliance, and a wide array of…” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
15	The BM Group	Exact match	Ottawa, ON, CanadaHQ recorded Sep 5, 2026	11-50	8 contacts →
	Exact match “The Business Management Group is a boutique accounting firm located in the heart of Westboro.” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
16	Frouin Group Professional Corporation	Exact match	Ottawa, ON, CanadaHQ recorded Sep 5, 2026	11-50	6 contacts →
	Exact match “Enterprise and Individuals We understand that your business is always evolving.” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
17	Boyer & Boyer, CPA	Exact match	Ottawa, ON, CanadaHQ recorded Sep 5, 2026	11-50	6 contacts →
	Exact match “Managing your own financial affairs is overwhelming and time-consuming!” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
18	Synapse Accounting Group	Exact match	Ottawa, ON, CanadaHQ recorded Sep 5, 2026	1-10	5 contacts →
	Exact match “We are a cloud-based accounting firm.” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
19	Leslie & Macleod, Chartered Accountants Cpas	Exact match	Ottawa, ON, CanadaHQ recorded Sep 5, 2026	11-50	5 contacts →
	Exact match Recorded description not available. Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
20	Accountrain INC	Exact match	Ottawa, ON, CanadaHQ recorded Sep 5, 2026	1-10	4 contacts →
	Exact match Recorded description not available. Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
21	Kingsford Consulting	Exact match	Ottawa, ON, CanadaHQ recorded Sep 5, 2026	1-10	4 contacts →
	Exact match “We are advisors to business owners and our focus is on increasing revenues and profitability.” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
22	Kowalski CPA	Exact match	Ottawa, ON, CanadaHQ recorded Sep 5, 2026	1-10	4 contacts →
	Exact match “Since 2017, Kowalski CPA has been offering a full range of services to individuals, businesses and estates.” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
23	Jordash Co. Ltee	Exact match	Ottawa, ON, CanadaHQ recorded Sep 5, 2026	1-10	4 contacts →
	Exact match “Jordash Co.” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
24	Elevate By Welch LLP	Exact match	Ottawa, ON, CanadaHQ recorded Sep 5, 2026	201-500	4 contacts →
	Exact match “Elevate by Welch LLP is designed as a one-stop shop for all your accounting needs.” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase
25	Balanced Solutions - CAS	Exact match	Ottawa, ON, CanadaHQ recorded Sep 5, 2026	1-10	3 contacts →
	Exact match “We specialize in partnering with small to medium sized businesses that are not yet ready for all the aspects (and cost!) of a full-time, in-house accounting team, Controller or…” Recorded in the RevenueBase company graph · Sep 5, 2026 · View company records in RevenueBase

RevenueBase SmartSearch

Describe a niche business in your own words. RevenueBase SmartSearch compares the meaning of your description with company business descriptions compiled in the RevenueBase company graph. Exact, Similar, Related and Broad control how closely companies must fit.

This list uses Exact for “professional services firms”. Each Exact match badge shows membership in that saved search; it is not an individual similarity score or a service-quality rating. Recorded descriptions are shown where available.

Showing 25 of 80 professional services firms based in Ottawa, Canada

See the full list, filter by size, metro and specialty, and access 633 tracked professional contacts with verified work emails. Direct dials are available where recorded.

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Professional services firms based in Ottawa, Canada at a glance

As of Sep 5, 2026

49.6%Verified-email coverage

15.9Average contacts per company

1-10Median size (employees)

Sep 5, 2026Page data refreshed

Companies by employee count

1-10

11-50

51-200

201-500

Email recency for this list is measured across the whole Canada list rather than for Ottawa, so it is reported there. Company counts and contact totals on this page are exact for Ottawa, over 80 companies.

How this list was built

The recorded descriptions help you assess these company matches. Check a company’s website for its current services and locations.

Source: The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase SmartSearch, the natural-language company search available to every RevenueBase user.
What qualifies: Company records associated with Ottawa, Canada whose business descriptions match “professional services firms” by meaning at the Exact setting. Descriptions are compiled in the RevenueBase company graph from public websites, profiles and company information where available; they are not guaranteed quotations from the company's website.
RevenueBase SmartSearch: Describe a niche company in your own words to find businesses by meaning. Exact, Similar, Related and Broad control the breadth of RevenueBase SmartSearch. This saved list uses Exact. Each row's Exact match badge shows inclusion in that search, not an individual score or a service-quality judgment.
Public preview: The public preview omits records without a verified work email. Where headquarters information is recorded, preview rows are also filtered to this page’s location. Dataset totals and geographic summaries describe the full matched records before these preview filters.
Match quality: RevenueBase's August 25, 2026 study assessed 4,198 description/company pairs across matching settings. The publisher reports 86% good or better at Exact. This evaluates the method across queries; it does not audit this individual list. Recorded company descriptions, where available, help you judge each match yourself. Read the full methodology: how the lists are built and what the study measures.
Ranking: Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification: Every displayed company carries at least one verified work email. RevenueBase tracks 633 professional contacts with verified work emails across the full matched dataset. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh: This page's figures were pulled from the company graph on September 5, 2026. Lists refresh periodically as the graph is re-checked.
Record context: Company records and descriptions can change. Check the company's website for its current services and locations.

Professional services firms by metro in Canada

Frequently asked

What is RevenueBase SmartSearch?

RevenueBase SmartSearch finds niche companies by the meaning of their business descriptions in the RevenueBase company graph. Exact, Similar, Related and Broad control how closely companies must fit your description. This list uses Exact for “professional services firms”; each Exact match badge shows search membership, not an individual similarity or quality score.

How many professional services firms are there based in Ottawa, Canada?

RevenueBase identified 80 company matches for professional services firms associated with Ottawa, Canada as of September 2026, using the meaning of business descriptions at Exact. This is the recorded matched set in the RevenueBase company graph.

What is the largest company on this list?

Welch LLP tops the displayed preview by professional contacts tracked in RevenueBase. Recorded headquarters appear in the company rows.

Which city in Canada has the most professional services firms?

Toronto leads Canada with 348 company records, followed by Calgary (166) and Montreal (165). Ottawa has 80.

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work limited free results with 500 credits to start. Upgrading provides access to the 633 professional contacts with verified work emails tracked across these 80 companies; direct dials are available where recorded.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 5, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase SmartSearch, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.