1. AB de Villiers:
At number one in the list of Fastest 15 Centuries in ODI is AB de Villiers for his 31-ball century against West Indies in 2015. De Villiers totally massacred the West Indies attack during his knock. He came in to bat in the 38th over when South Africa well-placed at 247-1 and made the most of the platform.
He brought up his century in 31 balls to records the fastest century in ODIs and then went on to score 149 (9 fours and 16 sixes).