Eight-time champion Roger Federer was confirmed as the second seed for Wimbledon on Wednesday, bumping Rafael Nadal down to third despite being ranked below the Spaniard.
Defending champion Novak Djokovic tops the draw while new world number one Ash Barty is top seed in the women's singles.
South African Kevin Anderson, runner-up to Djokovic last season, is fourth seed despite falling to eighth in the ATP rankings as Wimbledon used its special formula once again.
Twice Wimbledon champion Nadal will be seeded three, meaning he is likely to have to beat both Federer and Djokovic to claim his first title at the All England Club since 2010.
The Spaniard was critical of the Wimbledon's seedings formula this week, saying "it's not a good thing" that the grasscourt event is the only one of the four Grand Slams that does not stick rigidly to ATP rankings for seedings.
Wimbledon uses form over the past 24 months on grass to tweak the positions of the top 32 players in the men's draw.
While the women's seedings are in line with the WTA rankings, Wimbledon reserves the right to change the order to create "a balanced draw".
Anderson's promotion is bad news for French Open runner-up and world number four Dominic Thiem who drops to fifth seed and could play Djokovic, Federer or Nadal in the last eight.
Former runner-up Marin Cilic moved up from a world ranking of 18 to the 13th seeded spot.
Seven-time champion Serena Williams is seeded 11th as per her WTA ranking. Last year the American was bumped up to 25th seed despite being ranked 183rd after returning to the Tour following the birth of her daughter.
