William Angus Knight (22 February 1836 – 4 March 1916) was a Scottish Free Church minister and author and Professor of Moral Philosophy at St Andrews University.

He was born in the manse at Mordington in the Scottish Borders on 22 February 1836, the son of Rev George Fulton Knight.

[1][4] In the field of philosophy his work, editorial and other, includes his collection of Philosophical Classics for English Readers (15 volumes, 1880–90), some of which he wrote.

He presented to the trustees of Dove Cottage, Grasmere, the poet's former home, all the editions of Wordsworth's poems which he possessed.

His portrait by Elizabeth Alexander was presented to St Andrews University by the Ladies Literate in Arts whose admission he encouraged.