William Spiers Glenn MC (21 February 1877 – 5 October 1953) was a New Zealand rugby union player who played for the All Blacks on their 1905 tour.

[2] He was a keen sportsman, and as well as playing rugby, he became secretary of the Manaia Tennis Club.

[2] He made his All Blacks debut in 1904, playing against the touring British Isles team.

[1] In World War I, Glenn served with the Royal Field Artillery, reaching the rank of second lieutenant.

In 1916, he was awarded the Military Cross for conspicuous gallantry and ability as an observing officer.