The left-handed Jadeja follows skipper Rohit Sharma and Virat Kohli in quitting the shortest format soon after the seven-run win over South Africa in a thrilling final on Saturday.
"With a heart full of gratitude, I bid farewell to T20 internationals," Jadeja wrote in a social media post. "Like a steadfast horse galloping with pride, I've always given my best for my country and will continue to do so in other formats."
He added, "Winning the T20 World Cup was a dream come true, a pinnacle of my T20 international career. Thank you for the memories, the cheers, and the unwavering support."
Jadeja, 35, played 74 T20 matches for India. He took 54 wickets with his left-arm spin and scored 515 runs as a lower middle-order batsman since his debut in 2009.
Jadeja featured in all the matches for unbeaten India in the ninth edition of the T20 World Cup, which ended India's global trophy drought since the 2013 Champions Trophy.
Both Rohit and Kohli announced their T20 retirements in press interactions after the title win.
