Pontypool-born Taylor has signed a two-year deal, while Cooke and McIlroy have both signed one-year extensions.
Taylor, 22, made his Glamorgan debut in 2019 in the Vitality Blast against Essex Eagles, and made an explosive first-class debut in the Bob Willis Trophy fixture against Northamptonshire in August as he smashed an 88-ball century.
Taylor also played a rearguard innings to help secure a draw against Warwickshire at Sophia Gardens, and played seven Vitality Blast games in 2020.
Joe Cooke, 23, played two games in the Bob Willis Trophy, including his Glamorgan debut at Northampton, while Jamie McIlroy, the 26-year-old left-arm seamer from Builith Wells, did not feature after suffering an injury in an intra-squad friendly during pre-season.
Speaking on his contract extension, Taylor said: “This has been my home for a couple of years and it means quite a lot to me to keep playing for Glamorgan. I just want to kick on for next year and the seasons to come.
“It’s a privilege to play for Glamorgan. Innings like Northampton don’t come around very often, I know there’s a lot of hard work to do and if I can put in a few more performances like that I’ll be very happy and I’m sure the Club will be too.
“Playing at the top level is where you learn most, and the experience of playing this year will hold me in good stead for years to come.”
Director of Cricket, Mark Wallace, added: “Callum had a bit of a breakthrough this season with a fantastic hundred on debut and has shown how he can impact the side across all areas
“Along with what he’s shown with the bat, he’s got a lot of promise with the ball and is an outstanding fielder..
“Joe Cooke got a feel for what the first-class level is about and we’re looking forward to seeing him develop, and Jamie McIlroy showed some real promise through the winter.”
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