Winger Steve Michaels headlines a list of five players that will leave Hull at the end of the season.
Michaels, 30, will return to Australia having made more than 70 appearances in a two-year stint with the club.
Also leaving are youngsters Mike Adlard, Connor Bower, Zeus Silk and Jack Wray.
Head coach Lee Radford said: “Stevie has been a fantastic signing since he landed and he’s always given 110 per cent whenever he’s played for Hull FC.
“He’s a very committed player and hopefully, like the other guys who are leaving at the end of the season, we can send them out on a high note.”
Captain Gareth Ellis (retiring) and Mahe Fonua (Wests) are also departing the KCOM Stadium at the end of the year.
But the club has already announced the signings of winger Bureta Faraimo and prop Mickey Paea, while Dean Hadley, Jordan Abdull and Jack Logan will all return to the squad following spells out on loan.