William Main Page (8 October 1869 – 1 February 1940) was a British lawyer and Esperantist.
He went to Lasswade in his youth, and worked as an analytical chemist with an oil company in the Lothians.
Later, he entered the legal profession, and joined the firm of Cairns, McIntosh, & Morton.
He was a prominent layman in the Church of Scotland, and a well-known member of the General Assembly.
In the General Assembly he was regarded as an authority on hymnology, and was secretary of the Public Worship and Aids to Devotion Committee.