The "above expectation" figure compares with the pre-pandemic total of 2.5 million in 2019, the Turkish Tourism Board said.
Turkey has concentrated on attracting the UK market following the pandemic and a slump in the value of the Turkish lira against sterling. A pound now buys 38 Turkish lira compared with 18 two years ago.
As a result, operators including Jet2 and Tui have hugely increased their programmes to the destination. In May, Tui predicted it would take 40% more clients to the country in 2023 from across all its markets than it did in 2019.