Peter William Barlow (1 February 1809 – 19 May 1885) was an English civil engineer, particularly associated with railways, bridges (he designed the first Lambeth Bridge, a crossing of the River Thames in London), the design of tunnels and the development of tunnelling techniques.
In 1864 he patented a design for a cylindrical tunnelling shield, and obtained a provisional patent in 1868 for an improved design.