The Arsenal shareholder has been a vocal critic of the board's frugal policy in the past, and he has urged the club to splash out for the Manchester United forward.
The Uzbek-born Russian billionaire’s 29.9 percent stake makes him the Gunners’ second-biggest shareholder, and he has backed the move for the Manchester United striker.
Rooney is reportedly open to the possibility of moving to the Emirates, with Arsene Wenger said to be ready to meet his 20-25 million pound fee and hefty 250,000 pound weekly wage.
"He is a great player, there would be great success for Rooney [if he joined Arsenal], and for Arsenal too," Usmanov told CNBC.
The richest man in Britain admitted to the growing frustration over Arsenal’s failure to win a trophy since 2005, but he insisted that the board is completely behind Wenger.
"We as shareholders point to some drawbacks in the management of the club, but Wenger is a great coach and the club is progressing in the commercial sense," Usmanov said. "We should trust him.
"It is high time for the club to win the highest trophies in the European Champions League, but I believe in the club's future."
Usmanov was highly critical of the board following Robin van Persie's departure for Manchester United last summer, pinpointing a lack of ambition for the club's inability to compete for major titles.