Chelsea spent £747m on transfers last season, according to accounts published by Companies House.
The wage bill rose by 18% to £404m, the second highest in the Premier League.
Players costing £592m were sold for £203m, although accounting rules mean that generated a profit of £63m.
As of 30 June 2023 - after the first full year under the ownership of Todd Boehly's Clearlake Capital consortium - the total cost of the squad was more than £1bn.
A further £450m has been spent on transfers since 30 June, but that will be included in the 2023-24 accounts.