Our society is named after Johnian John Couch Adams (1819-1892), who was senior wrangler in 1843. John Couch Adams predicted the existence and position of the planet Neptune using nothing but mathematics: he considered discrepancies with the orbit of Uranus and used Kepler’s and Newton’s laws of planetary motion and gravitation. He held the Lowndean chair of Astronomy and Geometry in Cambridge for 33 years and won the Gold Medal of the Royal Astronomical Society. The Adams Prize, a prestigous University Mathematics Prize, is named in his honour.
There is a long list of other famous Johnian mathematicians:
From the St John’s website:
There are currently five Teaching Fellows in Mathematics, a number of Research Fellows and four Professors at St John’s College. We take about 15 undergraduates a year to read Mathematics, and they are taught by the Fellows, or by research students, in addition to attending the University lecture courses.