Oprah Winfrey
The media mogul and her longterm partner Stedman Graham have been together for over 25 years, but haven't made it official.
Mary-Louise Parker
The Weeds actress has a son with actor Billy Crudup and was briefly engaged to costar Jeffrey Dean Morgan, but has never been married.
John Cusack
The Raven actor has been previously linked to Neve Campbell and Minnie Driver, but has yet to tie the knot.
Winona Ryder
The Mr. Deeds actress has never walked down the aisle, but she was engaged to her Edward Scissorhands costar Johnny Depp in 1990.
Hugh Grant
Despite a 13-year relationship with actress Elizabeth Hurley, the Notting Hill star has never tied the knot.
Lauren Graham
The Parenthood actress and costar Peter Krause have been in a relationship since 2010, but they are in no rush to make it official.
Sheryl Crow
The musician has had several high-profile relationships with Owen Wilson, Eric Clapton and Lance Armstrong, but she's never been married.
Seth MacFarlane
The Family Guy creator briefly dated Game of Thrones beauty Emilia Clarke in 2012, but has yet to take the plunge.
Diane Keaton
The Something's Gotta Give actress has yet to make it official, despite being previously involved with Woody Allen, Warren Beatty and Al Pacino.
Jon Hamm
The Mad Men actor has been in a relationship with longtime love Jennifer Westfeldt since 1997, but has yet to pop the question.
Edie Falco
The Nurse Jackie actress may have two adopted children, but she has never tied the knot.
Matt Dillon
The There's Something About Mary actor was linked to costar Cameron Diaz in the 90s, but has never taken the plunge.
Kylie Minogue
The Aussie superstar has never tied the knot, despite longterm relationships with late INXS frontman Michael Hutchence and Olivier Martinez.
Owen Wilson
The Wedding Crashers funnyman has never wed, but he has dated A-list beauties like Sheryl Crow and Kate Hudson.
Marisa Tomei
The Oscar winner's famous exes include Robert Downey Jr., Lenny Kravitz and Christian Slater, but the brunette has never walked down the aisle.
Matthew Perry
The Friends star has dated Julia Roberts, Yasmine Bleeth, Lauren Graham and Lizzy Caplan, but has never wed.
Jeremy Piven
The Entourage star may play a family man onscreen, but he has yet to settle down in real life.