The star - who penned his first book, 'Laid In Chelsea', last year - is leaving the E4 reality show after five series.
According to the Daily Mail, he told reporters at the premiere of 'We're The Millers': "I've quit the show. I have done five seasons, I've had three breakups, I've come out as bisexual... I've done all that and I've decided the party's over for me.
'But I'll never close the door fully. There are lots of other projects in mind and people are talking. It's terrifying to be leaving the show as it's all I know on TV."
A source previously said Ollie had become fed up about the show's focus on his sexuality.
"They really tried to persuade him to stay but he’d made his mind up to go, which everyone respected," they told The Sun.
“There are bound to be lots of tears at the wrap party. He’s a very likeable guy on set.”
The sixth series of 'Made In Chelsea' starts later this year.