Rory McKenzie, Greg Kiltie and Ross Millen have agreed new Kilmarnock contracts while Chris Burke remains in talks over a new deal.
However, goalkeeper Jamie MacDonald and 18-year-old midfielder Ally Taylor have rejected contract offers.
MacDonald, 34, spent most of last season on loan at Alloa while Taylor made his first-team debut against Celtic in February, coming up against brother and former Rugby Park left-back Greg Taylor.
Midfielder McKenzie has agreed a two-year contract while Kiltie and Millen have both pledged their futures for next season.
McKenzie told the club's official website: "We started talks over a new deal before the coronavirus pandemic started so I'm delighted to get the deal completed.
"As I've said before, I'm a local boy who has been here for a long time and I know everyone at the club. I always wanted to stay at Kilmarnock and I'm really happy that has now become a reality."
Kiltie added: "I'm really pleased to sign a new contract and hopefully I can make a real mark in the team in the season ahead.
"Before the shutdown, I felt I was really starting to hit my stride again with Killie after a positive loan spell with Dunfermline.
Tomas Brindley and Kyle Connell have extended their contracts for next season after being involved with the first team squad over the past six months.