Peter Nicholson (20 July 1765  – 18 June 1844) was a Scottish architect, mathematician and engineer. Largely self-taught, he was apprenticed to a cabinet-maker but soon unaided his trade in favour of teaching and writing. He practised as an architect but is best remembered for his bookish work upon the skew arch (he never actually build up one himself), his invention of draughtsman’s instruments, including a centrolinead and a cyclograph, and his prolific writing on numerous practical subjects.