Sir Manuel Richard Hornibrook OBE (7 August 1893 – 30 May 1970) was an Australian builder and civil engineer. He founded the firm M R Hornibrook Pty Ltd that after merger with Baulderstone became one of the largest Australian civil engineering firms. Known as "MR", Hornibrook was knighted in 1960. He was highly respected and a builder of bridges across Queensland, New South Wales, Victoria, South Australia and Papua New Guinea as well as other major projects including Stages 2 (the Sails) and 3 of the Sydney Opera House.