One of nature's little jokes on humanity is that while women's fertility years are limited, men's generally aren't. And since older celebrity guys often have much younger girlfriends and wives, that means lots of famous men become fathers at an age when most men would otherwise be grandfathers. Here are some of the best-known.

  • Mick Jagger

    Between 1970 and 2000, the Rolling Stones frontman had seven kids with four women. The youngest child, son Lucas, was born in 1999 when Mick was 56.

    Simone Joyner, Getty Images
  • Bruce Willis

    Willis, now 58, has three daughters with ex Demi Moore. In 2012, his second wife (English actress and model Emma Heming) gave birth to his fourth daughter.

    Kevin Winter, Getty Images
  • Rod Stewart

    The legendary rocker-turned-crooner's third wife, model Penny Lancaster, had his eighth child a month after he turned 61 in 2011.

    Frank Micelotta, Getty Images
  • Paul McCartney

    Paul's marriage to Heather Mills ended very badly, but in 2003, it did produce one good thing: his fifth child. He was 61 at the time.

    Christopher Polk, Getty Images
  • Clint Eastwood

    Clint's only been married twice, but he has seven children by five women -- the most recent, daughter Morgan, was born to second wife Dina in 1996 when he was 66 years old.

    Slaven Vlasic, Getty Images
  • Hugh Hefner

    The now 87-year-old Playboy founder has four children. The youngest, son Cooper, was born in 1991 when Hugh was 66 -- making Cooper just a few years younger than his dad's current wife.

    Charley Gallay, Getty Images
  • Steve Martin

    Martin -- a multi-talented comedian, author, actor and musician -- has a long resume, but only added "father" to his personal bio in December of 2012 when he became a first-time dad at the age of 67.

    Michael Buckner, Getty Images
  • Luciano Pavarotti

    The late operatic tenor was 68 when his second wife gave birth to his fourth daughter in 2003. He passed away four years later.

    Oleg Nikishin, Getty Images
  • Robert De Niro

    De Niro was 68 in 2011 when he and second wife Grace Hightower used a surrogate to have daughter Helen Grace.

    Kevin Winter, Getty Images
  • Charlie Chaplin

    The silent film icon had 12 children, eight of them with fourth wife Oona (who was almost four decades his junior). The youngest, son Christopher, was born in 1962 when Chaplin was 73 years old.

    Hulton Archive, Getty Images