The Welsh actress - who was awarded the accolade for services to the film industry and to charity - was included in the Queen's Birthday Honours list last year and travelled to Buckingham Palace to pick up the prestigious honour today (24.02.11).
Accompanied by her 61-year-old husband Michael Douglas - who was recently treated for throat cancer - and the couple's two children Dylan, 10, and seven-year-old Carys, Catherine beamed as she was awarded the honour by the monarch's son.
When the announcement of the accolade was made last year, the 41-year-old actress admitted she was "humbled and thrilled" to have been given the award.
She said: "I am absolutely thrilled with this honour. As a British subject, I feel incredibly proud, at the same time it is overwhelming and humbling. And my mum and dad are delighted beyond belief."
Catherine shot to fame after starring in British TV drama 'The Darling Buds of May' in 1991 before moving to the US, where she got her big breakthrough playing Elena Montero in 'The Mask Of Zorro' in 1998.
However, her biggest success came in 2003 when she won the Academy Award for Best Supporting Actress for her role as Velma Kelly in the film adaptation of 'Chicago'.