Laura, 30, who played Lady Edith Grantham, and Michael, 26, who played servant Andy Parker, are said to be in the early stages of a relationship, after their on-set friendship developed further chemistry.
A source told The Sun that the pair got on very well when Michael joined the cast during the final season of the hit ITV drama, and things progressed from there.
'They started off as mates but quickly realised there was chemistry there and decided to start dating.
'It's very early days still but they are really enjoying each other's company. The best part is that since the show ended they have had a lot more time to spend with each other.
'Before that, most of their time together was at work.'
The couple apparently confirmed their relationship publically with a romantic walk through Hampstead Heath.
The couple, pictured here with co-stars Raquel Cassidy, Samantha Bond and Jim Carter, met while filming Downton Abbey's sixth and final season
Downton Abbey concluded in 2015 with a feature-length Christmas special, which saw Laura's character Edith finally marry happily after six seasons of heartache, including a jilting at the altar and an illegitimate child.
However Laura, although notoriously private about her personal life, has previously admitted that she is very unlike her on-screen persona.
When asked in an interview with the Daily Mail in 2014 whether she felt she ever channeled Edith in real life, she replied. 'No, I just couldn't! I wouldn't let that attitude filter through into real life in any way. It's abhorrent!'
Although they have been seen together, neither Laura or Michael have spoken out about or confirmed their relationship yet. We've got our fingers crossed for a cute couples snap on Instagram sometime soon!