The world number one downed old rival Andy Murray 3-6, 6-1, 6-2, 6-4 to claim a 12th career major and join Don Budge in 1938 and Rod Laver, in 1962 and 1969, as the only players to simultaneously possess the French Open, Australian Open, US Open and Wimbledon trophies.
Djokovic, 29, also put himself halfway to the calendar Grand Slam, last achieved by Laver 47 years ago.
But he did it the hard way as the final reached its conclusion, being broken in the eighth game of the fourth set as he served for the title and then squandering two championship points in the 10th before he sealed victory when Murray netted a backhand.
Playing in his 20th final at the majors and sixth in succession, the Serb superstar is the first man since Jim Courier in 1992 to win the Australian and French Opens back-to-back.
Victory also allowed Djokovic to stretch his winning record over 29-year-old Murray to 24-10 overall and 8-2 in Grand Slams.
