Tigers academy product Boyle is perhaps the most surprising out the three to leave the club, given the fact that the Rugby Football League place an high emphasis on home-grown players as part of the licencing criteria.
Clayton, 26, has had two stints at the club and helped the club gain promotion from National League One in 2007, whilst Feather joined the club from Bradford this season.
Coach Terry Matterson said: “As I have already said I didn’t plan too many change to the squad, with these four being the only senior players leaving the club.
“We have brought two new guys on board and I plan to promote two of the clubs promising young players, Jordan Thompson and John Davies, to the senior squad, but we are also still looking to bring a couple of additional signings on board.”
All three players have been linked heavily with new clubs in recent weeks with Boyle being touted for a move to Salford and Clayton to Halifax. Feather, meanwhile, has stated his intention to try and move to the NRL although rumours over the past week suggest he could be heading to France with Villeneuve.