Peter Alfred McLachlan (23 September 1867 – 27 October 1929) was a printer and member of the Queensland Legislative Assembly.

[1] Awarded the Pro Ecclesia et Pontifice by the pope, McLachlan died after entering the Mater Misericordiae Hospital to undergo an operation in October 1929.

[3] At the 1908 Queensland state election, McLachlan, for the Labour Party, and along with David Bowman, won the two member seat of Fortitude Valley.

He lost by four votes to the Ministerialist candidate, Thomas Welsby[5] but three years later, at the 1915 Queensland state election, he won the seat, beating his opponent Mr Lackey convincingly.

[6] He lost Merthyr at the 1920 state elections to Peter MacGregor, the National candidate[7] but regained the seat in 1923.