http://en.wikipedia.org/wiki/Arran_Fernandez
Arran Fernandez, England, born June 1995, is a mathematician who in June 2013 became Senior Wrangler at Cambridge University, aged 18 years, 0 months. He is probably the youngest Senior Wrangler ever.
In October 2010, when he began studying the Cambridge Mathematics Tripos aged 15 years and 3 months, he was the youngest Cambridge University undergraduate since William Pitt the Younger in 1773.
Prior to university, he was educated at home, and in 2001 he broke the age record for gaining a General Certificate of Secondary Education (GCSE), the English academic qualification usually taken at age 16, for which he sat the examinations aged five. In 2003 he became the youngest ever person to gain an A* grade at GCSE, also for Mathematics.
Starting in 2000 Fernandez has had several sequences published in the On-Line Encyclopedia of Integer Sequences (OEIS), the number theory database established by Neil Sloane.
His television work has included an appearance as a “Person of the Week” on Frank Elstner’s chat show on German TV in 2001, and an appearance on Terry Wogan and Gaby Roslin’s Terry and Gaby Show on British TV in 2003, when he beat mathematics populariser Johnny Ball in a live mental arithmetic contest, successfully extracting the fifth roots of several large integers.