She attended Saarland University in Saarbrücken with her initial plan for her education being in art history, but changed to experimental psychology after learning of its empirical nature.

[14] She was inspired by the work of psychologist, Hans Eysenck (who debunked psychoanalysis)[15] and decided to train in clinical psychology at the Institute of Psychiatry in London.

[17][18][19][16][20] Frith was mentored, during her early career, by Neil O'Connor and Beate Hermelin and has described them as pioneers in the field of autism.

[22] In 1985, while she was a member of the Medical Research Council's Cognitive Development Unit (MRC-CDU) in London, she published with Alan M. Leslie and Simon Baron-Cohen the article "Does the autistic child have a 'theory of mind'?

[26] The second is "weak central coherence"[27] by which she suggested that individuals with autism are better than neurotypical people at processing details, but worse at integrating information from many different sources.

[32] In her book on spelling,[8] she pointed out that some people can be perfectly competent readers, but extremely poor spellers, a group of dyslexics not recognised before.

The project is based in part on a paper written with Chris Frith: "Interacting Minds – a Biological Basis".

[45] In 2015 she was named chair of the Royal Society's Diversity Committee,[46] during which time she wrote about unconscious bias and how it affects which scientists receive grants.

[50] In 2013 Frith wrote on the visibility of women in science, by promoting an exhibition on female scientist portraits at The Royal Society.

[55] On 13 December 2017, she gave an interview to the Association for Child and Adolescent Mental Health,[56] in which she talked about her early life and her passion for autism research in children.

[61] In 2012, Frith became an Honorary Dame Commander of the Order of the British Empire (DBE), which was made substantive on 4 April 2019[62] after the German Government permitted dual British/German nationality.