Van Gaal was confirmed as David Moyes’ successor at Old Trafford on Monday and will take up his new post after Netherlands’ World Cup campaign in Brazil.
United finished seventh in the Premier League last season and Rooney insists United target next season is to win the Premier League.
“Van Gaal is a great appointment,” Rooney told talkSPORT.
“He’s obviously got a great track record at other clubs. I’m sure he’ll come in and do a great job for us.
“We’ve heard little things about him. Hopefully he can come in and get us back up the table.
“We have to improve on this season. Next year our aim is to win the Premier League title. This campaign was not good enough. We need to be fighting for that title.”