| Office: | Senator |
| Term Start: | 27 April 1938 |
| Term End: | 30 March 1946 |
| Constituency: | Nominated by the Taoiseach |
| Office1: | Teachta Dála |
| Term Start1: | June 1922 |
| Term End1: | June 1927 |
| Constituency1: | National University |
| Party: | Independent |
| Birth Date: | 18 May 1867 |
| Birth Place: | County Down, Ireland |
| Death Place: | Dublin, Ireland |
| Alma Mater: | University College Dublin |
| Education: | Belvedere College |
| Spouse: | Jane Magennis |
William Magennis (18 May 1867 – 30 March 1946) was an Irish politician and university professor.[1]
Born in Belfast, he was educated at Belvedere College, Dublin, and University College Dublin (UCD). In 1893 he was called to the Bar. He was professor of philosophy at Carysfort College and he held the Chair of Metaphysics at UCD.[2]
Magennis was first elected to Dáil Éireann as an Independent Teachta Dála (TD) for the National University constituency at the 1922 general election. He was elected as a Cumann na nGaedheal TD for the same constituency at the 1923 general election.[3]
In 1926, he was one of the founders of a new political party called Clann Éireann. The party advocated the abolition of the Oath of Allegiance to the British King, called for lower taxes and less legislation and was critical of the 1925 Boundary Commission agreement.[2] The party attracted little support and it did not win any seats at the June 1927 general election, including the loss of Magennis's seat. He was nominated by the Taoiseach to the 2nd Seanad in 1938 and served as an independent member until his death in 1946.[4]
Speaking during the debate of the 1923 Censorship of Films Act,[5] which was one of the first pieces of significant legislation to be passed by the Irish Free State. Magennis declared: "Purity of mind and sanity of outlook upon life were long ago regarded as characteristic of our people. The loose views and the vile lowering of values that belong to other races and other peoples were being forced upon our people through the popularity of the cinematograph".[6]
In 1942 Magennis spoke against the publication of obscene books such as The Tailor and Ansty, adding that his moral standards "... do not date back to Queen Victoria's days; they date back to Moses. The standards under which we operate go back to 1,500 years or so before Christ. If the Senator cares to accuse us of being old-fashioned, I am pleading guilty: I am so old-fashioned as to take my standards of life and conduct from Mount Sinai and not from Seán This and Seán That, whose books have been banned."[7]
In the ensuing debates it emerged that, while Magennis disapproved of sodomy, he did not know what it was. His opponent Senator John Keane pointed out that two men embracing in Land of Spices did not amount to sodomy, adding: "I think he might have used something less strong".[8]