The broadcaster confirmed the news on his Twitter account and paid tribute to his co-hosts Zoe Ball and Janette Manrara.
He wrote: "After 4 fantastic years it's time for me to hangup my glittery jacket and say goodbye to It Takes Two."
He added: "I've had the best time hosting alongside Janette and Zoe and I can't thank the amazing team enough for always putting on a great show. I've been welcomed into the Strictly family and will firmly hold that title dear to me.
"The time has come for me to pass on the baton to someone else and explore what else life has for me. Thank you Strictly, you will always have my heart...and my dancing feet."
In a statement, Kate Phillips, director of unscripted at the BBC, paid tribute to Rylan: "I want to thank Rylan for entertaining audiences so brilliantly for the past four years on Strictly It Takes Two. Rylan’s infectious personality, his stand out sass and his genuine love for all the glitz and glamour of the ballroom, has been a big part of It Takes Two’s continued success."
The BBC have said they will announce his replacement "in due course".
Despite leaving the show, Rylan is not departing the BBC and will be fronting the broadcaster's Eurovision coverage next month alongside a raft of presenters including Graham Norton, Alesha Dixon, Hannah Waddingham and Mel Giedroyc.
He will also continue to present his BBC Radio 2 show every Saturday from 3pm.
Rylan joined the Strictly spin-off in 2019, originally presenting alongside Zoe Ball until she departed and was replaced with professional dancer Janette Manrara.
The former X Factor contestant is set to host a reality show for Channel 4 called Sex Rated later this year.
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