The 28-year-old star recently jetted out to Los Angeles with her friend and Girls Aloud bandmate Kimberley Walsh.
It's claimed Cheryl met up with the 26-year-old dancer at her hotel room late one night and it's been reported he didn't leave until early the next day.
They then met up again two days later and met up twice - first at her hotel in West Hollywood and then again later on at a Japanese restaurant.
A source told UK newspaper Daily Mirror: 'Derek drove to her hotel both times in the same Audi sports car which Cheryl bought him for his last birthday.
'The second time he tried to hide beneath a hood upon entering the hotel but ended up using the main entrance which wasn't very discreet.
'Derek left about 90 minutes later, smiling from ear to ear. It's clear that he and Cheryl have patched up whatever differences they may have had.'
The source added: 'He later joined Cheryl and Kimberley Walsh at sushi place Roku, and the trio were laughing and giggling the entire time. Derek kept ruffling Cheryl's hair and poking her dimples - it was cute to watch.'