Courtney Love and Edward Norton
Hollywood types are notorious for their revolving-door marriages. Often you see magazines talking about some actor who's on their third, fourth, or eighth marriage. You can't always blame them because celebrities are under an enormous amount of pressure to look and act a certain way. It seems like celebrities get married more quickly, more often, and for shorter time periods than us regular people. Some celebrity marriages are as short as a week!
But what happens when a celebrity couple announces to the world that they are engaged but then the relationship fizzles out? It is much easier to break up than to wait and get divorced later. These couples didn't even make it to the altar.... 
Love and Norton met on the set of The People vs. Larry Flynt and had a six year relationship. They were engaged for about six months before calling it quits in 2001.
Ryan Reynolds & Alanis Morisette
Canadian duo Reynolds & Morisette first met a Drew Barrymore's birthday party in 2002. Their engagement lasted until 2007 when they mutually decided to call it off.
Reynolds has gone on to have several marriages, while Morisette married and wrote an album "Flavors of Entanglement" about her relationship with Reynolds.
Jude Law & Sienna Miller
Law caused a stir when he left his wife of six years, actress Sadie Frost, for Miller in 2003.
The relationship boosted Miller's career, and the couple had three years together before infidelities on Law's part.
Brad Pitt & Gwyneth Paltrow
Pitt and Paltrow costarred in Seven and spent three years together after meeting on set.
They split in 1997 just before their wedding, apparently because of conflicting lifestyle habits.
Mariah Carey and James Packer
Mariah got a giant diamond from her Australian businessman beau in January of 2016 - but by October, they were on the rocks. She was still wearing the 35-carat ring even after they broke up, though.
It reportedly cost $10 million!!
Charlize Theron & Sean Penn
A couple of Oscar winners, Penn and Theron's relationship lasted just over a year, before the couple quietly split in 2015.
The split was also an abrupt one, just months before their planned wedding and after Penn reportedly filed to adopt Theron's son, Jackson.
Emilio Estevez & Demi Moore
The Brat Pack duo were together just under two years before calling it quits. Apparent scheduling conflicts: both had film commitments which prevented them from spending much time together.
This only would happen in Hollywood!
Heather Locklear & Jack Wagner
The Melrose Place costars dated four years before announcing their engagement in August 2011, only to call off the wedding a few months later.
The two reportedly had an explosive argument which turned physical, and Locklear spent time in the hospital for substance issues shortly after the break up.
Jennifer Lopez & Ben Affleck
Perhaps the most overexposed couple in history, Affleck and Lopez called off their nuptials in December 2003 and broke up in January 2004.
Just six months later, Lopez wed fellow singer Marc Anthony, while Affleck began dating future ex-wife Jennifer Garner.
Emily Blunt and Michael Buble
The actor and the crooner were engaged in 2005 - he even wrote her a song!
They broke up after about three years - she's now married to John Krasinski of The Office, and he's married to Luisana Lopilato, an Argentinian model, so they're both doing okay.
Jennifer Love Hewitt & Ross McCall
Hewitt and McCall got engaged in 2007 before abruptly calling off nuptials in 2009.
Neither publicly disclosed a reason, though both were reportedly depressed following the break up.
Julia Roberts & Kiefer Sutherland
The couple had already spent tens of thousands of dollars planning their wedding only to have Roberts call the whole thing off just weeks prior.
Neither cited a reason, though Roberts rising star--she'd just received an Oscar nod for Pretty Woman--was said to play a role, as did mutual friend Jason Patric, with whom Roberts reportedly had an affair.
Chris Klein & Katie Holmes
Teen stars Klein (American Pie) and Holmes (Dawson's Creek) were engaged for two years before splitting in 2005.
Just weeks later, Holmes began dating Tom Cruise, whom she would later wed.
Miley Cyrus & Liam Hemsworth
Cyrus and Hemsworth dated four years before announcing their split in 2013.
The two reportedly had a torrid relationship, breaking up and getting back together several times, and their relationship reportedly inspired her song "Wrecking Ball." They were seen together at the Thor: Ragnarok premiere in 2017, though...
Hugh Hefner & Crystal Harris
Harris called off the vows just five days before she was set to walk down the aisle, though not before appearing on the cover of Hefner's notorious magazine as "Mrs.
Crystal Hefner." She and the late Hefner later reconciled and wed despite a 60 year age difference.
Winona Ryder & Johnny Depp
The Gen-X thespians made for an attractive if eccentric power couple for three years before calling it quits.
Depp even had several tattoos dedicated to Ryder drawn on his body.
Sheryl Crow & Lance Armstrong
The couple split in 2006 after a brief engagement, despite Crow trying on wedding gowns just weeks before.
Rumors persist that they'd had relationship ills for some time, and the split conspicuously occurred around the same time Armstrong became the subject of a steroid investigation.
Carson Daly & Tara Reid
Daly and Reid dated just over two years and broke up after six months of engagement.
Reid was confirmed to have struggles with substances and anorexia at the time.
Ginnifer Goodwin & Joey Kern
Goodwin and Kern enjoyed a year long engagement after a mutual friend set them up.
Though they did split in 2011, they remain good friends today.
Evan Rachel Wood & Marilyn Manson
Actor Wood and shocking musician Manson had a somewhat torrid on-again-off-again relationship beginning in 2007.
They got engaged in 2010, breaking up for good eight months later.
Kelly Osbourne & Matthew Mossheart
The foul-mouthed reality star met future fiance Mossheart at model Kate Moss's wedding.
Two years later, in 2013, they got engaged before calling it quits 18 months later.
Kim Kardashian & Reggie Bush
Bush and the infamous reality show and adult tape star enjoyed a well-publicized fling from 2007 to 2009.
Despite a rumored engagement, Kim broke it off on the pretense that he was " too young for her." Rumors of her infidelity persist, however.
Daniel Craig & Satsuki Mitchell
The current Bond and his producer girlfriend spent five years together, getting engaged in 2007.
They broke up in 2010, allegedly because Craig had an affair with Rachel Weisz...to whom he is now married.