Since arriving in Vancouver on Aug. 1, 2012, the six-foot-three centre-back has made 24 starts in 25 appearances in just over a year. This season, O'Brien has started all 17 of his appearances, including all four Amway Canadian Championship matches.
"I am extremely happy to sign a contract extension," said O'Brien. "I am enjoying my time in Vancouver and being a member of Whitecaps FC."
Prior to joining the Whitecaps, the 34-year-old defender made nearly 500 appearances with English clubs including Premier League sides Bradford, Newcastle, Portsmouth and Bolton.
The dual British-Irish citizen also played in the UEFA Champions League with Newcastle United and was a member of the Republic of Ireland's 2002 FIFA World Cup squad.
"Andy has been an important member of the club both on and off the pitch since joining the 'Caps last summer," said Whitecaps FC head coach Martin Rennie. "I am very pleased that we have locked up Andy for another year."
Also Thursday, the Whitecaps announced that striker Corey Hertzog will join NASL side FC Edmonton on loan.