The 37-year-old former England international quit at the end of the 2010-11 campaign but came out of retirement in January and played a key role in helping United finish second in the Premier League behind Manchester City.
"I am delighted, he knew he had made a mistake," Ferguson told MUTV at United's player of the year dinner. "He now realises if he plays 25 or 30 games next season, they will be of real quality.
"I think this will be Paul's last season. We know him very well. We have had him since he was a kid. We know how to use him."
With several United midfielders injured, Scholes made a shock return to the side as a substitute in the FA Cup third-round win at Manchester City in January and played 21 matches before the end of the season, scoring four goals.
Despite playing only half the campaign, Scholes finished third in the vote for England's Footballer of the Year, behind Arsenal striker Robin van Persie and United team mate Wayne Rooney.
There has been speculation that he could be included in England's European Championship squad which will be named by new coach Roy Hodgson on Wednesday.
Scholes, who won the last of his 66 England caps in 2004, has played nearly 700 games for United and scored 154 goals, helping the Old Trafford club win two Champions Leagues, 10 Premier League titles and three FA Cups.