Experts say the younger you are when you get married, the more likely your marriage is to end in divorce. Still, that hasn't stopped plenty of stars from taking the plunge before their 20th birthdays -- and while most of these unions predictably didn't last, a few did stand the test of time.
Melanie and 'Miami Vice' star Don Johnson have a long history. They hooked up in 1972 when she was just 14 and he was 22, and married four years later. It only lasted six months, but more than a decade later, they gave love another shot -- and were married from 1989 to 1996.
Bo and director John Derek met and fell in love on a 1973 film set when he was 47 and she was just 16. To dodge statutory rape laws in the US, the couple moved to Germany and wed three years later -- and stayed married until his death in 1988.
Milla and her 'Dazed and Confused' co-star Shawn Andrews swapped vows in 1992 when she was 16 (he was 21). Her mother, unamused, had the union annulled two months later.
In 1998, the 'Home Alone' star sent the tabloids into a frenzy when, at 17, he married actress Rachel Miner. They divorced in 2004 -- but by then, they'd already been separated for four years.
Thrice-wed Drew married her first husband, bar owner Jeremy Thomas, right after her 19th birthday in 1994 (she filed for divorce two months later). But even before that, the former wild-child had already been engaged to two other guys.
Before she was famously married to Joe DiMaggio and Arthur Miller -- and before she was even known as Marilyn Monroe -- a then 15-year-old Norma Jeane Baker swapped vows with cop James Dougherty, 20, in 1942. It lasted three years.
These days, the actress is happily engaged to Jason Sudeikis. But back in 2003, a then 19-year-old Olivia secretly wed Tao Ruspoli, the son of an Italian prince. The marriage lasted eight years.
As Loretta detailed in her memoir-turned-hit-movie 'Coal Miner's Daughter,' she wed Oliver "Doo" Lynn in 1948 at the age of 13 (or 15, depending on how old she really is). He famously bought her a guitar on their sixth anniversary, and a country legend was born. They were still married when he died in 1996.
Taran Noah Smith
Smith, who played youngest son Mark on the sitcom 'Home Improvement,' had just turned 17 when he married 33-year-old Heidi Van Pelt in 2001. They divorced in 2007.
Before Demi's marriages to Bruce Willis and Ashton Kutcher, she was wed to musician Freddie Moore. They tied the knot when she was 17, and while the union only lasted five years, she still uses his surname professionally.