Peter Neilson (1879 – 3 November 1948) was a New Zealand politician of the Labour Party.
He was born in Dunedin, became a baker, and was a business partner of James Wright Munro, also a Labour MP, from 1914. He had been active in the Socialist Party and Social Democratic Party, and had been on the Dunedin City Council and Maori Hill Borough Council.
Neilson had unsuccessfully stood in the Dunedin Central electorate in the 1931 election. He stood again for Dunedin Central in Labour's landslide win in the 1935 election, holding the seat until 1946 election, when he retired from Parliament. He was succeeded by fellow Labour member and future Minister of Defense Philip Connolly.
Neilson died on 3 November 1948, and was buried at Taruheru Cemetery, Gisborne.