By Sonia Oxley
Six-times champion Federer, the third seed, starts his campaign against Kazakhstan's Mikhail Kukushkin, and has been drawn in the same half as world number two Novak Djokovic whose 41-match winning streak was broken by the Swiss this month.
The Serb could face Federer in the last four, weeks after the former world number one beat him in the French Open semi-finals to inflict his first defeat of the year.
Had Djokovic won that match, he would have ousted Nadal from the number one spot but instead the Spaniard arrives at the All England Club with his top ranking in tact as he seeks a third Wimbledon crown.
Djokovic takes on France's Jeremy Chardy in the first round, while Nadal's potential semi-final opponent Andy Murray opens his campaign against Spaniard Daniel Gimeno-Traver.
Home favorite Murray, the fourth seed, warmed up for the tournament with victory at the Queen's Club grasscourt event, heightening public expectations of a first British men's grand slam champion since 1936.
The first-round limelight could be stolen by American John Isner and Frenchman Nicolas Mahut, who have been drawn against each other a year after their epic 11-hour battle in the same round, the longest ever tennis match.
"Isner vs Mahut drawing each other in the first round after last year is the most amazing thing I've seen in tennis!" Murray tweeted.
In the women's singles, champion Serena Williams was drawn in the opposite side of the draw to her sister and five-times champion Venus but in the same half as world number one Caroline Wozniacki and another pre-tournament favorite Maria Sharapova.
Serena, seeded seventh after being sidelined for almost a year because of life-threatening blood clots on a lung as well as a foot injury, takes on France's Aravane Rezai in the first round of what could be a tricky draw for her.
The Russian 2004 champion, who reached the French Open semi-finals this month after returning to some of her best form after two years of struggling with a shoulder injury, is seeded fifth and could meet Wozniacki in the quarter-finals.
Venus, back from an injury layoff, could pose an early threat to last year's runner-up Vera Zvonareva and the American knows how to win from a lower seeding having triumphed in 2007 as the 23rd seed, the same as she is this time.
(Reporting by Sonia Oxley; Editing by Ed Osmond)