Company lists · Data verified August 2026

Top 25 Accounting firms based in Ottawa, Canada

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

Compiled by the RevenueBase Data Team Verified Aug 28, 2026 93 companies tracked

There are 93 accounting firms headquartered in Ottawa, Canada (RevenueBase, August 2026). RevenueBase tracks 1,185 professional contacts across them, including 414 with verified work emails and 63 with mobile numbers. Toronto is the largest hub.

This list covers accounting firms headquartered in Ottawa, Canada, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Data current as of August 28, 2026.

93Companies

1,185Contacts tracked

414Verified emails

63Mobile numbers

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The 25 largest accounting firms based in Ottawa, Canada

Ranked by team size

Top 25 of 93 accounting firms based in Ottawa, Canada, ranked by team size, largest first. Data verified Aug 28, 2026. Click a count to unlock that company's people.
#	Company	HQ	Employees	Contacts	Verified emails
1	Marcil Lavallée	Ottawa, ON	51-200	108	60
2	Ggfl LLP	Ottawa, ON	51-200	93	42
3	Baker Tilly Ottawa LLP	Ottawa, ON	51-200	81	48
4	Logan Katz LLP	Ottawa, ON	51-200	80	57
5	Mccay Duff LLP	Ottawa, ON	51-200	66	39
6	Lekadir LLP	Ottawa, ON	51-200	46	40
7	Connelly & Koshy Professional Corporation	Ottawa, ON	11-50	33	10
8	Zenbooks	Ottawa, ON	11-50	18	12
9	AI TAX Consultants	Ottawa, ON	11-50	13	2
10	Hendry Warren LLP	Ottawa, ON	51-200	12	11
11	The BM Group	Ottawa, ON	11-50	9	4
12	Vaive And Associates Professional Corporation	Ottawa, ON	11-50	8	8
13	Armstrong Jones LLP	Ottawa, ON	1-10	8	7
14	Blueprint Accounting, INC	Ottawa, ON	1-10	8	5
15	Bouris Wilson LLP	Ottawa, ON	11-50	7	6
16	Paterson & Company	Ottawa, ON	11-50	7	5
17	Al-Mulla Cpas Professional Corporation	Ottawa, ON	1-10	7	4
18	L. Zinman & Company	Ottawa, ON	1-10	6	5
19	Boyer & Boyer, CPA	Ottawa, ON	11-50	6	3
20	Numetrica	Ottawa, ON	1-10	6	1
21	Synapse Accounting Group	Ottawa, ON	1-10	5	5
22	Leslie & Macleod, Chartered Accountants Cpas	Ottawa, ON	11-50	5	4
23	Aydin CPA Professional Corporation	Ottawa, ON	1-10	5	3
24	Ouseley Hanvey Clipsham Deep LLP	Ottawa, ON	11-50	4	3
25	Kowalski CPA	Ottawa, ON	1-10	4	2

Showing 25 of 93 accounting firms based in Ottawa, Canada

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Accounting firms based in Ottawa, Canada at a glance

As of Aug 28, 2026

1-10Median size (employees)

TorontoLargest hub · 416 HQs

63Contacts with mobile numbers

5Emails re-verified in last 30 days

Companies by employee count

1-10

11-50

51-200

201-500

501-1,000

Accounting firms by metro in Canada

Metro	Companies
Accounting firms in Toronto	416
Accounting firms in Calgary	244
Accounting firms in Montreal	213
Accounting firms in Mississauga	213
Accounting firms in Vancouver	194
Accounting firms in Edmonton	129
Accounting firms in Ottawa	93
Accounting firms in Surrey	76

How this list was built

Source: The RevenueBase company graph: 21.3 million companies and 398.9 million professional contacts resolved from primary sources.
Inclusion: Companies whose own business descriptions match “accounting firms”, with match quality audited by blind human judging, and headquartered in Ottawa, Canada.
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: Contact records re-verify on a rolling cadence; 5 contacts on this list were re-verified in the last 30 days.
Refresh: Lists are refreshed periodically as the underlying company graph is re-verified. Last verified Aug 28, 2026.

Frequently asked

How many accounting firms are there based in Ottawa, Canada?

There are 93 accounting firms headquartered in Ottawa, Canada as of August 2026 (RevenueBase).

What is the largest company on this list?

Marcil Lavallée, headquartered in Ottawa, tops this list with the largest team on record.

Which city has the most accounting firms?

Toronto leads with 416 headquartered companies, followed by Calgary (244) and Montreal (213).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 414 verified decision-maker contacts tracked across these 93 companies.

How current is this list?

The list is refreshed periodically as the underlying company graph is re-verified. It was last verified on August 28, 2026.

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About this data

RevenueBase is a B2B contact data platform. Its company graph covers 21.3 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, the same data that powers RevenueBase's B2B data products and the free research portal.