The Portugal forward has previously spoken about the appeal of one day playing for United again and rumours intensified when former Real president Ramon Calderon suggested that Ronaldo had become disillusioned in Madrid.
Those claims came in the wake of the departures of Angel Di Maria and Xabi Alonso, though Real's financial clout has seen them bring in the likes of Toni Kroos and James Rodriguez as replacements.
And, after scoring four times in the 5-1 win over Elche on Tuesday, Ronaldo spoke of his contentment with life at the Santiago Bernabeu.
"It's all speculation, speaking about my future… my future is Madrid. I'm happy," he said in quotes reported by AS.
"The season is going well and I'm not talking about my future, it doesn't make sense."
The 29-year-old also played down comments made by former Real boss Jose Mourinho, with the now Chelsea manager having revealed that the two have not stayed in touch since parting ways last year.
"It's nothing important, what's important is Madrid," he added of his countryman's comments. "On a personal level, things are going well and I want to help this shirt.
"I don't see a need to talk about things outside the club."
Ronaldo's four-goal haul against Elche came just three days after he scored a hat-trick in the 8-2 win at Deportivo La Coruna, taking his tally for the season to 12 goals in all competitions.
