Ferguson met the winger - now out for three months following ankle surgery - in Lisbon last week after speculation about the 23-year-old's future.
"It went well. We put across our points of view, where we stand and where the player stands," explained Ferguson. "I can say he'll be a Manchester United player next season. He won't be sold."
United will hope that Ferguson's comments at a press conference during the club's pre-season tour of South Africa will put an end to rumours linking Ronaldo with a switch to the Spanish champions.
Ronaldo, who scored 42 goals for United last season and whose contract runs until 2012, is currently recuperating after his surgery, which ruled him out of United's trip to South Africa.
Ferguson confirmed: "I did go and see him last week in Portugal and it was very amicable - there were no problems. That's where we are and we carry on. He's on crutches for the first four weeks, he'll be in rehabilitation for the next four and then the following four he'll be back into football training. The time mapped out is three months and we won't bring him back a day earlier than that."
