Full-back Wolfe-Elder is Carnegie’s leading scorer with 15 tries in 19 appearances this term, while centre Lucock – who has operated as an emergency fly-half for much of the campaign – passed 100 league appearances for the club in November.
Huddersfield-born centre Forsyth returned to the club from Leicester Tigers in 2015 having originally been developed in the Carnegie Academy and has missed just one Championship game all season.
Winger Watkins, meanwhile, has enjoyed a fine debut campaign having joined from league rivals Jersey Reds.
Ahead of Saturday’s final game of the season at home to London Scottish, Carnegie’s new director of rugby Chris Stirling said: “We are delighted to have agreed new deals with all four players.
“We are looking to continue to play an attractive brand of rugby next season and all four of these players have shown how well they can perform within our system.”