The 34-year-old Tait posted a picture of his OCI passport on Twitter to reveal his status.
The tearaway pacer, who had clocked the second fastest delivery in the history of the game at a speed of 161.1 kph in 2010, got married to Indian model Mashoom Singha in June 2014.
The 2007 ODI World Cup winner started dating the Indian model while playing the Indian Premier League with the Rajasthan Royals in 2010.
He retired from ODIs after the 2011 World Cup in India but he remained active in the Big Bash League. He was back in Australia's T20 team in the lead-up to the 2016 World T20.