The couple were glowing with anticipation for their wedding rehearsal dinner at NYC's Russian Tea Room in November 2000.
They cut quite a figure at the L.A. premiere of Chicago in 2002.
Catherine was famously pregnant with Carys throughout the 2003 awards season. She didn't win a Golden Globe on this night, but her name was called at the Oscars a month later.
Catherine channels Audrey Hepburn at the 2003 Nobel Peace Prize Awards Gala.
A couple of fresh fall looks in October 2006.
We're loving CZJ's wavy lob in April 2008.
After bounding back from tongue cancer, Michael looks pretty happy to be alive at the NYC premiere of Wall Street: Money Never Sleeps in November 2010.
They attend the Icon Award Presentation during the 22nd Annual Palm Springs International Film Festival in January 2011.
"Oh, no big deal, just standing next to a goddess here..." in 2011.
The longtime couple sport similar looks during New York Fashion Week in February 2011.
The chic duo step out in New York for the Children of Chernobyl Hosts Children At Heart Gala Dinner in November 2011.
They attend a 2012 Tribeca Film Festival event in April hand in hand.
"Personally, I think they're a little sweet." (Overheard at the 2012 Monte Cristo Awards, which of course doesn't actually honor the sandwich.)
Douglas puts the moves on his wife in 2013 during the annual Vanity Fair Oscar Party.
The couple look happy and healthy at Grey Goose's cocktail reception for The Film Society of Lincoln Center's 40th Chaplin Award Gala in April 2013, a few months before announcing what would turn out to be a temporary separation.
They hit the red carpet at the 2014 AFI Life Achievement Award Gala in Hollywood that June.
The fam shares a holiday vacation pic in December 2014.
The philanthropic pair attend the Phoenix House Public Service Award Dinner in January 2015.
Another glam night out, here at the Saturday Night Live 40th Anniversary Celebration in February 2015.
The patrons of the arts attend the opening night celebration for The Library at The Public Theater in April 2015.
The whole family is there to watch Michael Douglas be honored in Jerusalem with the Genesis Prize, presented by Israeli Prime Minister Benjamin Netanyahu, in June 2015.
Doing a Marvel movie makes premieres a family affair, here at the London premiere of Ant-Man in July 2015 with son Dylan and daughter Carys.
The longtime tennis fans enjoy a day date at the 2015 U.S. Open in September.
NEXT GALLERY: Celebrity Couples We Admire
Catherine uploaded this adorable family photo to Instagram in order to express her thanks for her husband and children.