Denys Colquhoun Flowerdew Lawson (22 January 1906 – 10 September 1975), known as Sir Denys Lowson, 1st Baronet from 1951, was a financier and Conservative Party politician.
Born in Warwickshire, he was the youngest child of James Gray Flowerdew Lowson and Adelaide Louisa née Scott. His father was a physicist and businessman involved in the paper manufacturing business.
Following education at Oxford, he was called to bar at the Inner Temple in 1930. He began working in banking and stockbroking and in 1935 became managing director of Security First Trust. He soon became managing director or chairman of a number of unit trust companies.
He was Sheriff of the City of London for 1939–40 and Lord Mayor of London for 1950-51. During this term he was created a baronet "of Westlaws in the County of Perth". He was Master of the Glaziers' Company for 1947-48, the Loriners' Company for 1950-51, and the Gold and Silver Wyre Drawers for 1951-52, and Prime Warden of the Shipwrights' Company for 1955-56.
From 1949-52 he sat as a member of the London County Council representing the Cities of London and Westminster.
In 1973 his financial dealings came under investigation by the Department of Trade and Industry. A report published in July 1974 found he had traded in a highly irregular manner, enriching himself at the expense of his co-investors. He was forced to resign from the directorships of his companies and a number of law suits were begun against him by individuals while the Director of Public Prosecutions served him with a summons. However, Lowson died before the case reached court.
First Lord Mayor to undertake a round the world tour during his period of office (Records of the Basketmakers' Company of the City of London 1907-67, compiled by Sidney Alfred Perrin, p 211)