The Illinois Legal Market Leaderboard
3 minute read • Updated 24 June 2026
In our US state leaderboard series, we look at the law firms with largest partner headcount and strongest recent headcount growth in each US state. Here are the firms that have lead the way in the Illinois legal market over the last 12 months.
Illinois' Partner Headcount Growth Has Lagged Behind Similarly Sized Legal Markets
Illinois' growth lands at the lower end of US legal markets of a similar size, growing
+1% in the past year compared to Florida's
+3%.
Ranked: Which Law Firms are Leading Growth in Illinois?
United States, Illinois, Partners, Firms with >10 Partners, May 2025 - May 2026
Partners with multiple locations have been evenly distributed across each
Banking & Finance Practices Have Seen The Highest Headcount Growth, While Intellectual Property Decreased
Banking & Finance topped the chart with +3% growth in the last year. This was followed by Corporate (+2%) and Insurance (+2%) practices.
Texas Is By Far The Most Popular Destination and Source For Partner Moves
17 Partners made the move from Texas to Illinois in the past year, accounting for 27% of all incoming Partners. Likewise, 21% of all Partner departures were Texas-bound (12 Partners).
New York was the second most common source (7 Partners), and the destination for
3 departing Illinois Partners. Washington DC and Michigan were the second most common destination for leaving Partners (5 Partners each).
Investment Funds Has Seen The Most Public Client Matters From the Top 10 Firms
13.8% of publicly disclosed client matters in the top 10 ranking firms were in the investment funds industry, followed by 10.8% in healthcare & life sciences and 10.4% in financial services.
This tracks with the wider Chicago economy. World Business Chicago identifies finance and professional services as core industries in the region, alongside healthcare and life sciences and fintech as key growth sectors.
Kirkland & Ellis drove a large proportion of these matters, with 33% of Illinois public matters in the top 10 firms belonging to them.
Note on methodology
Source: Publicly-available data tracked by Pirical Legal Professionals
Location: Illinois, United States
Timeframe:
May 2025 - May 2026
Score weightings:
- 50% headcount growth
- 50% current headcount size
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