Age is nothing but a number, at least for these celebrity couples.

1) Catherine Zeta-Jones and Michael Douglas: The actress is 25 years younger than her husband of almost 12 years.

2) James Woods and Kristen Bauguess: Woods' girlfriend is 20 years old while he's 66.

3) Beyonce and Jay Z: Hip-hop's famous couple has an 12-year difference. Beyonce is now 32 and Jay Z is 43.

4) Stephen Moyer and Anna Paquin: The True Blood co-stars have a 13-year age difference. Moyer is now 43 and Paquin is 30. The couple tied the knot in August 2010 and had twins in 2012.

5) Megan Fox and Brian Austin Green: The couple, who also has a 13-year age gap, married in 2010 and had their first baby two years later.

6) Ashton Kutcher and Demi Moore: Although they are no longer together, Kutcher and Moore had a 15-year age difference. Their relationship began in 2003 but ended in 2011 after he allegedly cheated.

7) Tom Cruise and Katie Holmes: While they are another couple that is no longer together, Cruise and Holmes had a 16-year age gap. They were married in 2006 and divorced in 2012.

8) AnnaLynne McCord and Dominic Purcell: The actress is 17 years younger than her boyfriend and fellow actor. She's now 26 and he's 43.

9) Alec Baldwin and Hilaria Thomas: The couple wed in 2012 and has a 26-year age difference.

10) Doug Hutchison and Courtney Stodden: Hutchinson married Stodden when she was only 16 in 2011. He was 51.

11) Woody Allen and Soon-Yi Previn: Allen had an affair with Soon-Yi who was the adopted daughter of his wife at the time. The couple is still together despite their 35-year age difference.

12) Hugh Hefner and Crystal Harris: The couple may have one of the biggest age differences ever. Hefner is 87 and Harris is 27.

13) Brad Pitt and Angelina Jolie: The couple has a 12-year age difference. Pitt is now 49 and Jolie is 38.

14) Mariah Carey and Nick Cannon: Carey is 10 years older than her husband.

15) Ryan Reynolds and Blake Lively: Reynolds is 11 years older than Lively who is now 26.