Lee, who faced a public backlash following his stint in CBB, told fans last night that he was leaving the social networking site, saying he hoped they understood.
In a message, the Blue singer said: "Don't need this in my life, Twitter isn't for me. It's too negative, I don't need it no one would, sorry to my fans. Hope you understand xxx."
It's not clear exactly what has prompted Lee's sudden departure from Twitter, however he did fall foul of trolling after leaving the CBB house last month.
During his time on the C5 show, Lee became embroiled in a love triangle with glamour model Casey Batchelor and US reality star Jasmine Waltz.
His behaviour prompted a lot of reaction from fans and viewers and Lee later said he felt like he had "murdered someone".
Don't need this in my life twitter isn't for me. It's too negative, I don't need it no one would, Sorry to my fans. Hope you understand xxx— Lee Ryan (@LeeRyanMusic) March 6, 2014
During an interview on This Morning, Lee said: "It's got a little too much for me... I'm not going to lie. It's like... I feel like I've murdered someone. I feel like I've done something to small kittens or small dogs or something.
"I did go in there as a single man, I wasn't married or anything. Yeah, I did get myself in a pickle, and yeah it came across really bad and I understand that, but the treatment I'm getting, I think it's way over the top if I'm honest."
After his announcement last night, Lee retweeted a post about karma, which said: "When people insult you, don't take offence, don't take it personally, but do listen to their words.
"They are telling you how they see the world, and they are telling you the exact negative qualities they possess."