Ancelotti spent two years in charge of Chelsea from 2009-2011, helping the Blues win the league title before moving onto Paris Saint-Germain.
The Italian has said that he enjoyed his time in the Premier League and opened the door on a future return to England.
"I loved England and I was very happy at Chelsea," Ancelotti told reporters.
"I liked the atmosphere, the fans. I have great memories. I'd go back, but it depends on how long this adventure at Real Madrid lasts."
Ancelotti takes his Real Madrid side to Liverpool in the Champions League on Wednesday.