Chelsea spent more than £35million on agents' fees in the 12 months to the start of February, new data published by the Football Association shows.
The Blues invested heavily in new recruits last summer, bringing in players like England defender Ben Chilwell from Leicester and Germany international Kai Havertz from Bayer Leverkusen.
The FA's report on intermediary fees between February 1, 2020 and the same date this year found the west London club spent £35,247,822.
The Manchester clubs were the next biggest spenders, with City's outlay £30,174,615 and United's £29,801,555.
The lowest top-flight spenders on agents' fees were West Brom, whose outlay was £4,222,059.
In total, Premier League clubs spent £272,220,223 on such fees between February 1, 2020 and February 1, 2021, despite clubs suffering major losses due to the coronavirus pandemic.
The Centre for Economics and Business Research found top-flight clubs had spent a combined £1.24billion in the summer 2020 transfer window.
The total was actually higher than the amount spent by Premier League sides between February 1, 2019 and January 31, 2020, when the figure was £263,368,860.
Spending on agents' fees was down by more than £9million in the Championship compared to the previous 12 months.
Second-tier clubs splashed out £40,753,529 in total between February 2020 and February 2021, with league leaders Norwich spending the most – £6,827,037.
Spending on agents was also slightly down in Leagues One and Two compared to the previous 12 months.