John Bruce Glasier (25 March 1859 – 4 June 1920) was a Scottish socialist politician, associated mainly with the Independent Labour Party.

Glasier was born in Glasgow as John Bruce, but grew up near Newton Ayr.

After the death of his father in 1870, he returned to Glasgow and followed his mother in adding the additional name of "Glasier", thereafter using Bruce as his middle name.

He joined the Socialist League split from the SDF, becoming the secretary of its Glasgow branch until 1889.

In 1905, Glasier became the editor of Labour Leader, but left the post in 1909 and resigned from the ILP National Council, along with Hardie, Ramsay MacDonald and Philip Snowden.