Sir Thomas Peirson Frank (23 July 1881 – 12 November 1951) was a British civil engineer and surveyor. He is particularly remembered as "the man who saved London from drowning" in the Blitz. Frank was born in 1881 at Kirkbymoorside, Yorkshire, the son of farmer Thomas Peirson Frank and Jane Shepherd. He was elected to the Smeatonian Society of Civil Engineers in 1937 and was president of the Royal Town Planning Institute in 1944. He was elected president of the Institution of Civil Engineers for the November 1945 to November 1946 session.