He sits ahead of Australian Steve Smith in second place, following India's 2-1 test series win in Australia.
England captain Joe Root, who helped his side beat Sri Lanka in the opening test, and India wicketkeeper Rishabh Pant have made considerable gains after their match-winning performances in the Galle and Brisbane Tests.
Root, a formerly top-ranked batsman, has returned to the top five with his highest rating points tally (738) in two years after scoring a first-innings 228 to help win the first Test against Sri Lanka by seven wickets.
Root has advanced six places, overtaking the likes of Pakistan's Babar Azam and India's Cheteshwar Pujara in the process.
Left-hander Pant's unbeaten 89 on the last day in Brisbane that guided India to a sensational three-wicket victory over Australia, sees him attain a career-best 13th position to become the top-ranked wicketkeeper in the batting rankings.
Australia batsman Marnus Labuschagne's first-innings century took him past Virat Kohli to third position behind Smith and Williamson with a career-best 878 rating points, captain Tim Paine moved up three spots to 42nd after scores of 50 and 27 while fast bowler Josh Hazlewood leapfrogged New Zealander Tim Southee to the fourth spot after grabbing six wickets in the match, including a haul of five for 57 in the first innings.
