Moshiri was born in Iran, and his parents left just before the revolution in 1979. Moshiri has said that his Father was "an army Doctor who trained as a pathologist and later became a senior military judge", and his mother "came from Iran's leading publishing house, Kayhan, which is now based in London." He was educated at University College London, and trained in the UK as a chartered certified accountant.
Moshiri and longstanding Business partner Alisher Usmanov were co-owners of Red & White Holdings, which bought 14.65% of the shares in Arsenal F.C. from former club vice-chairman David Dein in August 2007. On 18 September 2007, Red and White Holdings increased their stake in Arsenal to 21%, and on 28 September 2007 to 23%, a week after Moshiri announced that he wanted at least a 25% holding in the football club. As of June 2012, Red and White Holdings have acquired at least 29.72%. Arsenal managing Director Keith Edelman told BBC Radio 5 Live, "They've said previously they are not going to make a bid for the company and they want to be long-term shareholders."
In February 2016 it was announced that Moshiri had sold his stake in Arsenal Football Club to Red & White Holdings partner Usmanov in a bid to raise capital required to launch a takeover at Everton F.C. On 27 February, the club officially confirmed Moshiri's purchase of a 49.9% stake in the club, which was ratified two weeks later by the Premier League. He currently part owns Everton F.C.