Her name comes from both of her grandmothers, one named Catherine and the other named Zeta (who was named after a ship her great-grandfather had sailed on)
Had a tracheotomy as a child, which left a scar
Reportedly turned down a marriage proposal from producer Jon Peters in 1996 because she wanted to be known as an actress rather than just a Hollywood wife
For her role in Chicago, reportedly requested a short bob haircut so that her face would be visible and audiences would know that she did all of her own dancing
Performed an Oscar-nominated song from Chicago at the 2003 Academy Awards while eight-months pregnant with her second child
She took home a statue that night as Best Supporting Actress for her performance in the film
Named Commander of the Order of the British Empire (CBE) in 2011
Built a house in her hometown of Swansea so her children would grow up aware of their Welsh heritage
Shares a birthday with her husband, Michael Douglas, who is 25 years her senior