QPR have been given a cash boost after the family of the world's fifth richest man bought a 20% stake in the club.
Mittal (right) pictured with fellow QPR investor Bernie Ecclestone
The son-in-law of Indian steel magnate Lakshmi Mittal, who is reportedly worth £50bn, will join Bernie Ecclestone and Flavio Briatore on the club's board.
"This investment is a great stepping stone towards the future development of the club," said a club statement.
"It supports the ambition of the current shareholders to reach the Premier League in the near future."
QPR are currently bottom of the Championship, but they could now potentially join near neighbours and FA Cup third round opponents Chelsea in the transfer market, should Mittal wish to spend his cash.
"The family is excited about becoming involved with QPR," said Mittal's son-in-law, Amit Bhatia.
"As a family, we love sport and particularly enjoy English football, and alongside Bernie and Flavio, we hope that we can improve the club's performance, with the ultimate ambition of a place in the Premier League."