Company lists · Data refreshed September 2026

Top 25 Big 4 business consulting firms based in Ireland

RevenueBase identified 100 big 4 business consulting firms headquartered in Ireland as of September 2026 and tracks 7,847 professional contacts across them, including 2,702 with verified work emails. Dublin is the largest hub.

This list covers big 4 business consulting firms headquartered in Ireland, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 21, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, 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 HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 21, 2026 86% judged on-target in blind review
100Companies
7,847Contacts tracked
2,702Verified emails
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The 25 largest big 4 business consulting firms based in Ireland

Ranked by team size
Top 25 of 100 big 4 business consulting firms based in Ireland, ranked by team size, largest first. Data refreshed Sep 21, 2026. RevenueBase Smart Search rates how each company's information relates to big 4 business consulting firms: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Indirect evidenceDublin 2, IrelandHQ checked Sep 21, 20261,001-5,0002,952 contacts →

Indirect evidence

“KPMG is a leading provider of professional services, offering a range of audit, tax and advisory services to a broad range of domestic and international clients across all sectors…”

Source: RevenueBase Database · checked Sep 21, 2026
2Partial evidenceDublin 2, IrelandHQ checked Sep 21, 2026501-1,000698 contacts →

Partial evidence

“Forvis Mazars in Ireland is a leading international audit, tax, advisory and consulting firm.”

Source: RevenueBase Database · checked Sep 21, 2026
3Partial evidenceDublin, IrelandHQ checked Sep 21, 2026201-500521 contacts →

Partial evidence

“BDO Ireland LLP is an accountancy and business advisory firm that provides Audit, Tax, Deals, and Consulting, Risk & Outsourcing (CR & O) services to entrepreneurial, growing and…”

Source: RevenueBase Database · checked Sep 21, 2026
4Indirect evidenceDublin 2, IrelandHQ checked Sep 21, 202651-200129 contacts →

Indirect evidence

“At Crowleys DFK we believe in creating value for our clients.”

Source: RevenueBase Database · checked Sep 21, 2026
5Indirect evidenceDublin 18, IrelandHQ checked Sep 21, 202651-200119 contacts →

Indirect evidence

“One brand.”

Source: RevenueBase Database · checked Sep 21, 2026
6Indirect evidenceDublin, IrelandHQ checked Sep 21, 202611-5078 contacts →

Indirect evidence

“OSK have been providing quality and professional business advice to Irish businesses since 1985.”

Source: RevenueBase Database · checked Sep 21, 2026
7Indirect evidenceCork, IrelandHQ checked Sep 21, 202651-20074 contacts →

Indirect evidence

“At Baker Tilly, we care about you and the impact you make.”

Source: RevenueBase Database · checked Sep 21, 2026
8Indirect evidenceDundalk, IrelandHQ checked Sep 21, 202651-20068 contacts →

Indirect evidence

“UHY FDW is a leading audit, tax and advisory practice in Ireland, driven to achieve a better future together, for our people, our clients and our communities.”

Source: RevenueBase Database · checked Sep 21, 2026
9Indirect evidenceDublin, IrelandHQ checked Sep 21, 202651-20066 contacts →

Indirect evidence

“With an Irish heritage dating back to 1958, we’ve built a legacy in expertise, simplicity and an unrelenting commitment to client success.”

Source: RevenueBase Database · checked Sep 21, 2026
10Indirect evidenceTralee, IrelandHQ checked Sep 21, 202611-5060 contacts →

Indirect evidence

“Welcome to CSG, a leading accountancy firm in Ireland providing professional services to businesses of all sizes.”

Source: RevenueBase Database · checked Sep 21, 2026
11Indirect evidenceDublin 2, IrelandHQ checked Sep 21, 202611-5045 contacts →

Indirect evidence

“Based in Dublin, Walsh O’Brien Harnett is one of Ireland’s top 20 professional advisory firms offering a wide range of accounting, audit, tax, advisory and corporate services.”

Source: RevenueBase Database · checked Sep 21, 2026
12Indirect evidenceSligo, IrelandHQ checked Sep 21, 202651-20041 contacts →

Indirect evidence

“Gilroy Gannon brings to its clients a unique partnership - people drawn together from the major international accounting firms, industry and small practice with the common goal of…”

Source: RevenueBase Database · checked Sep 21, 2026
13Indirect evidenceRathfarnham, IrelandHQ checked Sep 21, 20261-1026 contacts →

Indirect evidence

“Leonard & Company of Rathfarnham, Dundrum, South Dublin, is a multidisciplinary professional services accountancy practice that is committed to providing a comprehensive range of…”

Source: RevenueBase Database · checked Sep 21, 2026
14Indirect evidenceTullamore, IrelandHQ checked Sep 21, 202611-5025 contacts →

Indirect evidence

“BCA provide a full range of proactive financial, taxation, business advisory, audit, company secretarial and commercial services to our broad range of clients.”

Source: RevenueBase Database · checked Sep 21, 2026
15Indirect evidenceKells, IrelandHQ checked Sep 21, 202611-5024 contacts →

Indirect evidence

“At Woods and Partners, our experience is reflected in the services we offer.”

Source: RevenueBase Database · checked Sep 21, 2026
16Indirect evidenceLimerick, IrelandHQ checked Sep 21, 202611-5023 contacts →

Indirect evidence

“HDS, founded in 2004, is an established practice of professional advisors with offices at RiverPoint, one of Limerick’s most recognisable and prestigious landmark buildings.”

Source: RevenueBase Database · checked Sep 21, 2026
17Indirect evidenceSantry, IrelandHQ checked Sep 21, 202611-5020 contacts →

Indirect evidence

“Having the right accountant on your team is a critical part of your success and because there’re so much choice out there it can be tricky to find the one that fits exactly with…”

Source: RevenueBase Database · checked Sep 21, 2026
18Indirect evidenceGalway City, IrelandHQ checked Sep 21, 202611-5018 contacts →

Indirect evidence

“Since our formation in 1984, we have developed to be a top practice located in Galway.”

Source: RevenueBase Database · checked Sep 21, 2026
19Indirect evidenceEnnis, IrelandHQ checked Sep 21, 202611-5017 contacts →

Indirect evidence

“AMQ is a multidisciplinary firm of Accountants, Registered Auditors and Business Consultants.”

Source: RevenueBase Database · checked Sep 21, 2026
20Indirect evidenceMullingar, IrelandHQ checked Sep 21, 202611-5015 contacts →

Indirect evidence

“At Stephens Cooke & Associates we are committed to providing a comprehensive range of services to ensure that we are not simply a service provider, but a firm that work in…”

Source: RevenueBase Database · checked Sep 21, 2026
21Indirect evidenceBlackrock, IrelandHQ checked Sep 21, 20261-1015 contacts →

Indirect evidence

“Chartered accountants, auditors and tax consultants”

Source: RevenueBase Database · checked Sep 21, 2026
22Indirect evidenceClonmel, IrelandHQ checked Sep 21, 202611-5014 contacts →

Indirect evidence

“At OGBP we aim to understand our clients’ business`s and work with them in achieving their goals.”

Source: RevenueBase Database · checked Sep 21, 2026
23Indirect evidenceDublin, IrelandHQ checked Sep 21, 202611-5014 contacts →

Indirect evidence

“Hugh McCarthy & Associates is a leading professional audit and advisory firm providing professional services to a range of industries and clients including private individuals…”

Source: RevenueBase Database · checked Sep 21, 2026
24Indirect evidenceKildare Town, IrelandHQ checked Sep 21, 202611-5013 contacts →

Indirect evidence

“McMahon Auditors Accountants is a well-established firm of accountants, tax advisors, and business consultants, proudly serving clients from our offices in Kildare, Naas, and…”

Source: RevenueBase Database · checked Sep 21, 2026
25Indirect evidenceSutton, IrelandHQ checked Sep 21, 202611-5011 contacts →

Indirect evidence

“We focus on building strong relationships with our personal and business clients by getting to know them, their plans and their aspirations.”

Source: RevenueBase Database · checked Sep 21, 2026

Showing 25 of 100 big 4 business consulting firms based in Ireland

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Big 4 business consulting firms based in Ireland at a glance

As of Sep 21, 2026
34.4%Verified-email coverage
78.5Average contacts per company
11-50Median size (employees)
15.0%Largest-city concentration · Dublin
Sep 21, 2026Page data refreshed

Companies by employee count

1-10
39
11-50
44
51-200
9
201-500
3
501-1,000
2
1,001-5,000
2

Email recency for this list is measured worldwide rather than for Ireland, so it is reported there. Company counts and contact totals on this page are exact for Ireland, over 100 companies.

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among big 4 business consulting firms, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source
The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
What qualifies
Companies headquartered in Ireland whose own description of what they do matches “big 4 business consulting firms”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search
RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names big 4 business consulting firms), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude
Companies whose own description does not clearly place them among big 4 business consulting firms, and records with no verified work email. Companies headquartered outside Ireland are excluded even when they keep an office there.
Match quality
In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
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 listed company carries at least one verified work email, 2,702 across the full list. 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 21, 2026. Lists refresh periodically as the graph is re-checked.
Corrections
Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names big 4 business consulting firms, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many big 4 business consulting firms are there based in Ireland?

RevenueBase identified 100 big 4 business consulting firms headquartered in Ireland as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

Kpmg Ireland, headquartered in Dublin, tops this list with the largest team on record.

Which city has the most big 4 business consulting firms?

Dublin leads with 15 headquartered companies, followed by Cork (4) and Limerick (4).

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 2,702 verified decision-maker contacts tracked across these 100 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 21, 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 Smart Search, 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.