The midfielder has formally put pen to paper on a contract that expires in the summer of 2018, 22 years after he first moved to Camp Nou.
The Spain interantional agreed to terms on a deal last week to end speculation that he could seek a move away from Camp Nou. And he has now signed the contract, which expires in four and a half years, shortly after his 34th birthday.
"The player Andres Iniesta has signed a new contract this Monday which will keep him at Barcelona until 2018," a club statement read. "The event took place a the club offices and was also attended by president Sandro Rosell, vice president for sporting affairs Josep Maria Bartomeu, sporting director Andoni Zubizarreta and the player's agent.
"From the 2017-18 season the contract will be extended automatically annually, provided that the player plays the right number of games each season."
Iniesta first joined Barca when he was 12 years old in 1996 and the contract could see him remain with the club for a total of 22 years.