The creative Argentine midfielder, a notable absentee from Diego Maradona's 2010 World Cup side, will be 36 when the contract concludes in 2014, the year Brazil host the next World Cup.
The deal was a long time on the table and the final decision to accept Riquelme's terms earlier this week split the club's board of directors down the middle, with president Jorge Amor Ameal's vote tipping the balance 9-8 in favour.
"We've finished the way we all wanted...The most important thing is that I'm going to be at the club a lot longer to defend the colours I love so much," Riquelme told reporters at the signing.
However Riquelme, a part of the most successful era at Boca in which they won four South American Libertadores Cup titles between 2000 and 2007, will not be darting straight back onto the pitch this weekend.
He is recovering from knee surgery in May and wants to get fully fit before playing again, possibly coming back in the team's seventh or eighth match of the Apertura championship that started last weekend with Boca being held 1-1 away to Godoy Cruz.
Riquelme helped Argentina reach the 2006 World Cup quarter-finals where they lost on penalties to hosts Germany.
Due to personal differences he was overlooked by Maradona for this year's finals, which ended at the same stage for Argentina in a 4-0 rout by the same opponents.
