Andy Carroll, Adrian and Samir Nasri will leave West Ham when their contracts expire next month.
Striker Carroll, 30, has scored 34 goals in 142 appearances over seven seasons at the club since arriving from Liverpool, and goalkeeper Adrian, 32, has played 150 times in six years.
Former France international Nasri, 31, made six appearances since joining on 31 December 2018.
That marked the day he completed an 18-month doping ban.
In a statement, co-chairmen David Sullivan and David Gold highlighted Carroll's spectacular scissor-kick goal against Crystal Palace in January 2017, and Adrian's heroics in an FA Cup third-round penalty shootout against Everton in 2015, when he scored the winning kick.
"Both have provided us and our fellow supporters with some unforgettable moments, whether they were sensational scissor kicks and unstoppable headers in Andy's case, or penalty saves and goals in Adrian's," they said.
"They can both be assured of warm welcomes whenever they return to London Stadium and we wish them, as well as Samir Nasri and the young players whose contracts are up this summer, the very best for their future careers."
Spanish striker Toni Martinez will also leave on 30 June, as will midfielders Moses Makasi and Noha Sylvestre and defenders Vashon Neufville and Josh Pask.
West Ham are also open to the possibility of strikers Lucas Perez and Javier Hernandez leaving the club.
Perez, who has has been linked with Spanish club Alaves, has two years left on his contract but failed to make an impression last season following his £4m arrival from Arsenal.
Hernandez expressed a desire to leave for Spain in January but that was put on hold amid uncertainty over the future of Marko Arnautovic.
The former Manchester United striker, bought by the Hammers for £16m from Bayer Leverkusen in 2017, has a year remaining on his contract.