John Murtagh Macrossan (1832 – 30 March 1891)[1] was an Australian politician of the late 19th century in the parliament of Queensland.

In 1889 Macrossan expanded upon this success by introducing new regulations which included provisions for a system of inspections by representatives of the miners.

After advocating on the issue for many years, in October 1890 Macrossan brought forward a motion to bring about the separation of the north.

Then Premier Samuel Griffith moved an amendment that it was desirable to have separate legislative authorities in southern, northern and central Queensland, which was carried.

In February 1890 Macrossan attended the conference on federation held at Melbourne with Griffith, who was then leader of the opposition, and in 1891 he was one of the Queensland representatives to the first Constitutional Convention.