The X Factor alumni were both finalists on the reality TV show with Olly coming second in 2009 and Diana coming fourth in 2008.
She made her film debut in The Perfect Wave and her television acting debut in the comedy series Give Out Girls, both of which premiered in 2014.
According to reports from The Sun, the cheeky Essex boy is having fun with newly-single Diana, 24, and the pair have had an "obvious attraction" to one another.
A source told the newspaper: "They've always had a soft spot for each other.
‘Olly in particular has a lot on his plate due to his X Factor commitments and music.
But it’s one to keep an eye on.’ Diana, 24, previously confessed that the 31-year-old star was her X Factor crush and even supported him on his UK tour in 2013.
Vickers was selected for the live shows and was mentored by Cheryl Cole in the girls' category alongside Alexandra Burke and Laura White.