John Underhill (c.1545–1592) was an English academic, involved in controversy, and later Bishop of Oxford.
In 1576, Underhill offered opposition to Robert Horne, Bishop of Winchester, in his visitation of the college.
Underhill, however, had recourse to the Chancellor of Oxford, then Robert Dudley, 1st Earl of Leicester.
[1] Bruno's work La Cenere de le Ceneri (The Ash Wednesday Supper) may refer to Underhill in the character Nundinio.
On 8 December 1589, he was elected Bishop of Oxford on the recommendation of Francis Walsingham, succeeding Hugh Curwen after a long vacancy.