1. Peter Krause and Lauren Graham

What they worked on together: The TV series Parenthood — they played siblings Adam and Sarah Braverman.
The two first met way back in 1995 on set of Caroline in the City but they didn't start dating until starring on Parenthood together. Lauren told Good Housekeeping, that she had a rule about not dating any actor-types and tried to keep her relationship with Peter in the friend zone. She later admitted that their friendship evolved into a relationship. She said, "It was like, You like me, and I like you. It gave me an understanding of life: This is how things happen, and it's completely random."
2. Machine Gun Kelly and Megan Fox
What they worked on together: An upcoming indie thriller called Midnight In The Switchgrass
The two met on set for their movie back in March 2020, but production was paused because of the pandemic. Then, a source told E! News that they'd actually started "hanging out a lot since their movie was shut down." Megan also starred in his music video "Bloody Valentine" in May and the two became Instagram official soon after.
3. Samira Wiley and Lauren Morelli

What they worked on together: The TV series Orange is the New Black — Samira played Poussey and Lauren was a writer on the show.
Samira and Lauren met on set of Orange Is the New Black and in an interview with Bust Magazine, Samira shared that she actually fell in love with Lauren's mind before she even met her in person. She said, “I was really attracted to Lauren’s mind first before I met Lauren the person. I got her script and I was like: ‘This person’s really talented, I can’t wait to meet this person.'” At the time, Lauren was still married to a man and had only just discovered that she was a lesbian, so she and Samira started off their relationship as friends before blossoming into something more. They finally got married in 2017.
4. Chrissy Teigen and John Legend
What they worked on together: Chrissy starred in John's 2007 music video "Stereo."
Chrissy shared that she first met John when she was hired to play his love interest in his "Stereo" music video. She also revealed that after the shoot, the two went back to John's hotel, ate In-N-Out, and hooked up. She told Cosmopolitan, "We didn’t ever say goodbye that night.” They got together a few months later and got married in 2013.
5. Rob McElhenney and Kaitlin Olson

What they worked on together: The TV series It's Always Sunny in Philadelphia — Rob plays Mac and Kaitlin plays Dee.
Rob and Kaitlin actually started secretly dating during Season 2 of It's Always Sunny and the rest of the cast didn't know about their relationship until two seasons later. Kaitlin shared that originally, she wanted a serious relationship while Rob wanted to keep it casual, however Kaitlin was convinced she knew how he really felt way before he did.
6. Beanie Feldstein and Bonnie Chance Roberts
What they worked on together: The 2019 movie How to Build a Girl — Beanie starred as Johanna Morrigan and Bonnie was a producer.
Before meeting Bonnie, Beanie shared that she wasn't a big relationship person. They first met on set for the movie How to Build a Girl, and Beanie told Teen Vogue that as soon as she met Bonnie suddenly everything made sense. She said, “Whoa! Now I get it…. I get why people write songs.”
7. Will Smith and Jada Pinkett-Smith

What they worked on together:The Fresh Prince of Bel-Air... kinda — Jada auditioned to play Will's girlfriend on the show but she didn't end up getting the part.
They first met in 1994 on the The Fresh Prince of Bel-Air set and began dating soon after. They eventually got married in 1997. They have two kids, Jaden and Willow. In 2020, they also shared that they went through a brief separation in 2016, but have reconciled and are still together today.
8. Eliza Taylor and Bob Morley
What they worked on together: The TV series The 100 — Eliza played Clarke and Bob played Bellamy.
Eliza and Bob first met on the set of The 100 and throughout the course of the series, fans had pleaded for writers to give the two a romantic storyline. However, they actually kept most of their real-life relationship a secret and surprised fans with their marriage announcement in 2019.
9. Mariska Hargitay and Peter Hermann

What they worked on together: The TV series Law & Order: SVU — Mariska plays Olivia Benson and Peter played Trevor Langan.
Mariska and Peter first met during Season 2 of SVU and during their first date, Mariska admitted she was instantly drawn to him. She told InStyle, "I just about passed out when I saw him there. I thought, that's my husband." They got married in 2004.
10. Joseph Morgan and Persia White
What they worked on together: The TV series The Vampire Diaries — Joseph played Klaus Mikaelson and Persia played Bonnie's mom, Abby Bennett.
The two met during the third season of TVD and then went on to create a short film together called Revelation. They didn't officially confirm their relationship until 2013, but they were spotted on several occasions together so fans assumed they were dating. They got married in 2014.
11. Gwen Stefani and Blake Shelton
What they worked on together: The TV series The Voice — they're both judges.
Gwen and Blake first met back in 2014 on The Voice, however, both were married to other people at the time. Then in mid-2015, both Blake and Gwen had gotten divorced from their respective spouses and confirmed dating rumors in November. Since then they've continued working on The Voice and released music together. They finally got engaged in October.
12. Kit Harington and Rose Leslie

What they worked on together: The TV series Game of Thrones — Kit played Jon Snow and Rose played Ygritte.
They were first rumored to be dating in 2012 after photos of them holding hands surfaced. Then, for years after, Kit denied a romantic relationship with Rose, while also admitting he's very private about his love life. At the 2016 Olivier Awards, they made their first public debut as a couple, and in 2018 they got married. They just had a baby together too!
13. Andrew Rannells and Tuc Watkins
What they worked on together: The Broadway play The Boys in the Band
They actually first met after being cast as boyfriends in the stage production of The Boys in the Band and fell for each other while doing press for the play. Later on, they also worked together on Showtime's Black Monday and reprised their roles for Netflix's adaptation of The Boys in the Band.
14. Ginnifer Goodwin and Josh Dallas
What they worked on together: The TV series Once Upon a Time — Ginnifer played Snow White and Josh played Prince Charming.
Josh and Ginnifer first met on set of Once Upon A Time and started dating soon after. They fell in love almost instantly and in an interview with People, Josh said "It hit me like a blinding light." They finally got married in 2014. Together, they have two kids.
15. Ross Lynch and Jaz Sinclair
What they worked on together: The TV series Chilling Adventures of Sabrina — Ross played Harvey Kinkle and Jaz played Roz Walker.
They met on set of CAOS and were rumored to be dating early on and eventually their characters became love interests on the show. They finally confirmed their relationship last year on TikTok and have been together since.
16. Penélope Cruz and Javier Bardem

What they worked on together: The 2008 movie Vicky Cristina Barcelona — they played exes Juan Antonio and María Elena.
They originally met in 1992 but didn't begin dating until 2007 when they reuinted for Vicky Cristina Barcelona. They were seen spotted together on numerous occasions, but didn't make an official public appearance until 2010 at the Goya Awards. They also got married in 2010 and have two kids together.
17. Ryan Gosling and Eva Mendes

What they worked on together: The 2012 movie The Place Beyond the Pines — they played exes Luke and Romina.
They'd met years before The Place Beyond the Pines began filming, but officially started dating quietly while working on the movie together. They've remained private about their relationship throughout the years, however they sometimes will talk about each other in their family during interviews. Together they have two kids, Esmeralda and Amada.
18. Kelly Ripa and Mark Consuelos
What they worked on together: The TV series All My Children — they played love interests Hayley Vaughan and Mateo Santos.
They first met on the set of All My Children where they played love interests. Their chemistry was instant and so they started dating in secret. Then, in 1996, after only dating for a few months, they eloped. Together, they have three kids.
19. Grace and Trai Byers
What they worked on together: The TV series Empire — Grace played Anika and Trai played Andre.
Grace and Trai were very quiet about their romance at first, but a source told Us Weekly that they started dating shortly after meeting on set. The source also shared that they had an "instant attraction" and eventually got married in 2016.
20. Tig Notaro and Stephanie Allynne

What they worked on together: The 2013 movie In a World... — Tig played Cher and Stephanie played Nancy.
The two became fast friends after meeting on set. Stephanie shared that when she met Tig she still identified as straight. As she started to fall in love with Tig she eventually came to realize that even though she thought she was in love with her exes, she actually wasn't in love with them at all. She told Cosmo, "I was so into Tig and I was falling in love with her and I didn't know how to identify it because I thought I was straight." They finally got married in 2015.
21. Kirsten Dunst and Jesse Plemons

What they worked on together: The TV series Fargo — they played husband and wife Peggy and Ed Blumquist.
They met and became friends while working together on Fargo but didn't officially start dating until a year and a half later. When reminiscing about their time working together Jesse told People, "I knew that she would be in my life for a long time." Together they have one son, Ennis.
22. And finally, Gwyneth Paltrow and Brad Falchuk
What they worked on together: The TV show Glee — Gwyneth guest-starred as Holly Holiday and Brad was one of the show's creators.
Brad and Gwyneth met when she guest-starred on Glee and at the time, both were recently divorced from their longtime spouses. Then, they were first publicly spotted together a few months later at Robert Downey Jr.'s 50th birthday and a source told People that the two were "very happy together." They didn't make their relationship Instagram official until late 2015. They finally got married in 2018 and have been together since.