Cartlidge was born in London, to Derek, an English father and Bobbi, a German-Jewish refugee mother.

Cartlidge worked in two more Leigh films: in Career Girls she played one of the lead roles, Hannah, at the ages of both 20 and 30, and in Topsy Turvy she was a madam in a Paris brothel.

She was due to play the lead role in Polish director Lech Majewski's 2004 film The Garden of Earthly Delights—that of an art historian dying of cancer—but she left shortly before production began.

Established at the Sarajevo Film Festival, an annual bursary is awarded by "an elected curator, chosen by the (Foundation) Trustees from a wide and eclectic number of Katrin Cartlidge’s friends and colleagues...(to) a new creative voice...

"[8] Following her death, British singer Morrissey dedicated a performance of his song "Late Night, Maudlin Street" at the Royal Albert Hall to Cartlidge, describing her as a "brilliant person and fantastic actor".