Kit Harington and Rose Leslie started dating after co-starring in HBO's "Game of Thrones." They announced their engagement in September 2017.
Keri Russell and Matthew Rhys, who star as KGB agents posing as a married couple in American suburbia in the FX spy drama "The Americans," have been dating since 2013 and welcomed their first child together in late May 2016.
Morena Baccarin, also known for her roles on "Firefly" and "Homeland," and Ben McKenzie, also known for his roles on "The O.C." and "Southland," met when Baccarin joined the cast of "Gotham" part way through the show's first season. The two started dating and announced their engagement in September 2015. Baccarin gave birth to the couple's first child, daughter Frances Laiz Setta Schenkkan, on March 2, 2016.
"Once Upon a Time" co-stars Ginnifer Goodwin and Josh Dallas began dating in 2011 and became engaged in October 2013. They married on April 12, 2014, and Goodwin gave birth to the couple's first child, a son, in May 2014.
Anna Paquin and Stephen Moyer met on the set of their HBO series "True Blood" and married in 2010. They had twins in September 2012.
Justin Theroux and Jennifer Aniston met while filming "Wanderlust." The two announced their engagement in August 2012 and were married in a top-secret ceremony at their Los Angeles home on Aug. 5, 2015.
Mila Kunis and Ashton Kutcher originally met while co-starring on "That '70s Show," but it wasn't until 2012 that they started dating. They had a daughter together in October 2014 and got married on July 4, 2015.
Brad Pitt and Angelina Jolie met on the set of "Mr. and Mrs. Smith," although Pitt was married to Jennifer Aniston at the time. Despite tabloid rumors of an affair, Pitt and Jolie said they didn't start dating until after Pitt was divorced.
"Madame Secretary" star Téa Leoni has been dating her on-screen husband, Tim Daly, since December 2015.
Maggie Q got engaged to Dylan McDermott, her co-star on the short-lived CBS drama series "Stalker," in January 2015 after dating for several months.
Eva Mendes and Ryan Gosling, co-stars in the movie "The Place Beyond the Pines," began dating in September 2011 and had a daughter together in September 2014.
Ryan Reynolds and Blake Lively met on the set of "The Green Lantern." The two were married in 2012.
Jennifer Carpenter and Michael C. Hall met and married while playing brother and sister on the Showtime serial killer drama "Dexter." They filed for divorce in December 2010 after two years of marriage.
Channing Tatum met actress Jenna Dewan on the set of their movie "Step Up." They began dating shortly after filming had finished and became engaged in September 2008. They were married on July 11, 2009.
Claire Danes and Hugh Dancy began dating after appearing together in 2006's "Evening." They were married in 2009.
Tom Hanks married actress Rita Wilson in 1998. The two first met on the set of Hanks' sitcom "Bosom Buddies" but later developed a romantic relationship while working on the film "Volunteers."
Johnny Depp and Amber Heard first met on the set of 2011's "The Rum Diary" and began dating in 2012. They married on Feb. 3, 2015, but Heard filed for divorce just 15 months later.
Laurence Fishburne and Gina Torres met while filming "The Matrix Reloaded" and were married in September 2002. They have one child, a daughter named Delilah, born in 2007
Jennifer Garner and Ben Affleck met while filming "Daredevil" in 2003, though they didn't begin dating until 2004. The couple married in 2005 and had two daughters and a son, before breaking up in June 2015.
Tom Cruise met Nicole Kidman while the two were filming 1990's "Days of Thunder." They pair were married on Christmas Eve 1990 and stayed together until 2001.
Cruise also dated Penelope Cruz, whom he met on the set of "Vanilla Sky." The two dated for three years before splitting.
Halle Berry and French actor Olivier Martinez met in 2010 while filming the movie "Dark Tide." They married in July 2013 and had a son, Maceo, in October 2013. They announced they were divorcing in the fall of 2015 after two years of marriage.
Natalie Portman and choreographer Benjamin Millepied met on the set of 2010's "Black Swan," which Portman earned an Oscar for. The two were married in 2012.
Jada Pinkett Smith met Will Smith in 1990 on the set "The Fresh Prince of Bel-Air" when she auditioned for the role of his character's girlfriend. Although she didn't get the role, the two became friends and started dating in 1995. They've been married since 1997.
While "Twilight" co-stars Kristen Stewart and Robert Pattinson did their best to keep their off-screen romance quiet, they were frequently photographed together. They stayed together until Stewart had an affair in 2012 with her "Snow White and the Huntsman" director Rupert Sanders. They briefly reconciled before breaking up again in the spring of 2013.
Andrew Garfield and Emma Stone met in 2010 while filming "The Amazing Spider-Man." They dated until they broke up in 2015.
Sarah Michelle Gellar and Freddie Prinze Jr. first met while filming "I Know What You Did Last Summer" in 1997, but didn't start dating until 2000. The pair married in 2002.
David Arquette and Courteney Cox met while filming "Scream." They married in 1999 but divorced in 2012.
Michelle Williams and Heath Ledger met on the set of "Brokeback Mountain." They had a daughter together in 2005, but split shortly before Ledger died in 2008.
Javier Bardem and Penelope Cruz first met while filming the 1992 Spanish comedy-drama "Jamón Jamón." They began dating while filming "Vicki Cristina Barcelona" in 2007 and were married in 2010.
Josh Duhamel met Fergie when The Black Eyed Peas filmed a cameo on his show "Las Vegas" in 2004. They became engaged in 2007 and were married in 2009.
Kelly Ripa and actor Mark Consuelos met while co-starring on the soap opera "All My Children."
Susan Sarandon's character in "Bull Durham" may have fallen for Kevin Costner's character, but in real life she fell in love with fellow co-star Tim Robbins. The two began dating in 1988 and had two sons together but split in 2009.
Goldie Hawn and Kurt Russell met while filming the wartime romance "Swing Shift" in 1983 and are still together today.
Kelly Preston first met John Travolta in 1987 while filming "The Experts." They married in 1991.
Kevin Bacon has been married to actress Kyra Sedgwick since Sept. 4, 1988. The two met on the set of the PBS version of Lanford Wilson's play "Lemon Sky."
Annette Bening married Warren Beatty on March 12, 1992, one year after meeting on the set of "Bugsy."
Jessica Alba fell for production assistant Cash Warren in 2005 while making "Fantastic Four." The couple got engaged in 2007 and were married in 2008.
Julia Roberts met her husband, cameraman Daniel Moder, while filming "The Mexican" in 2000.
Elizabeth Taylor and Richard Burton infamously met on the set of the cinematic debacle "Cleopatra." They married and divorced each other twice.
Humphrey Bogart met Lauren Bacall on the set of 1944's "To Have and Have Not" when he was 45 and she was 19. Despite Bogart being married at the time, they began an affair. Bogart divorced his wife in February 1945 and married Bacall in May 1945. The two remained together until Bogie's death in 1957.
Katherine Hepburn and Spencer Tracy met while making "Woman of the Year" in 1942. Despite Tracy being married to actress Louise Treadwell at the time, they began a secret relationship that lasted until his death 26 years later.
"Slumdog Millionaire" co-stars Dev Patel and Freida Pinto started dating after meeting on the set of the Oscar-winning film. They split up in December 2014 after nearly six years together.
"Heroes" co-stars Hayden Panettiere and Milo Ventimiglia dated from 2007-2009.
Alyson Hannigan and Alexis Denisof met on the set of "Buffy the Vampire Slayer" and have been married since 2003.
Vincent Kartheiser and Alexis Bledel (best known for "Gilmore Girls") began dating after meeting on "Mad Men" and announced their engagement in March 2013. They were married in California in June 2014.
Hugh Jackman met his wife, Deborra-Lee Furness on the set of an Australian television prison drama. They married in April 1996.
Cory Monteith and Lea Michele began dating on the set of "Glee" and were still a couple when Monteith died of a drug overdose in July 2013.
Actor Eddie Cibrian and country singer LeAnn Rimes were both married when they met and began an affair while filming Lifetime's "Northern Lights." The two divorced their respective spouses and got married in 2011. In 2014, the two starred in their own VH1 reality show, "LeAnn & Eddie."
Tracy Pollan and Michael J. Fox met on the set of "Family Ties." They married in 1988.
"It's Always Sunny in Philadelphia" co-stars Kaitlin Olson and Rob McElhenney began dating in secret during season two of the series. They married in September 2008 and have since had two sons.
Lauren Graham and Peter Krause first met in 1995 while they both were guest stars on "Caroline in the City." While they stayed friends over the years, their romance didn't blossom until they began starring together as brother and sister on the sitcom "Parenthood" in 2010.
Rachel Bilson, who previously dated her "The O.C." co-star Adam Brody for three years, started dating Hayden Christensen after they met on the set of the movie "Jumper." They became engaged in 2008 and had their first child, a daughter named Briar Rose, in October 2014.
"Revenge" co-stars Josh Bowman and Emily VanCamp have been dating since late 2011.