7. Keri Russell & Matthew Rhys
Keri Russell and Matthew Rhys first met when they were in their 20s, but nothing romantic happened between them - though Rhys later admitted that he was quite smitten with the curly actress.
In 2014 the two met again on the set of The Americans, where they played married Russian spies – and this time, off-screen romance quickly followed. The couple has one son together, born in 2016, and are also co-raising Russell’s children from her previous marriage to Shane Deary.
8. Kirsten Dunst & Jesse Plemons
Kirsten Dunst and Jesse Plemons met in 2015 while playing married high school sweethearts on the second season of Fargo, when Dunst was still dating long-time boyfriend, actor Garrett Hedlund.
The two became good friends, and after Dunst and Hedlund separated their friendship evolved - and in 2016 they were photographed kissing. The couple got engaged in 2017, and in 2018 Dunst gave birth to their first child, a boy.
9. Lauren Graham & Peter Krause
Lauren Graham and Peter Krause first met in 1995 when they both were guest stars in the show Caroline in the City, and became friends. However, they only became a couple years later - in 2010 - when they met again on a tv show set, this time playing the roles of – brace yourselves - brother and sister on the show Parenthood.
The couple lives together in Los Angeles, and are co-raising Krause’s son from his relationship with ex-girlfriend Christine King.
10. Alyson Hannigan & Alexis Denisof
Alyson Hannigan and Alexis Denisof met in the late 90s when they were both playing fan-favorite characters on the cult show Buffy the Vampire Slayer, and later on its spin-off, Angel.
Even though they were busy vampire-slaying, they still found the time to fall in love IRL. They got married in 2003 and have two daughters, and remain one of Hollywood’s unbreakable couples.