Peter Michael Butler CBE (31 May 1901 – 24 September 1995) was a New Zealand seaman, trade unionist, communist and local politician.

At age 16 Butler joined the Mercantile Marine reserve, serving mostly in the North Sea for the remainder of World War I.

After the war Butler became one of the leaders of a militant faction in the seamen's union and briefly courted communist ideology, which he rejected strongly later in life.

[1] During the late 1920s and early 1930s (the duration of the Great Depression), Butler served as secretary of the Wellington Builders' and General Labourers' Union.

In the 1985 Queen's Birthday Honours, Butler was appointed a Commander of the Order of the British Empire, for services to the trade union movement.