During his time at the club he has been a big hit, winning the Champions League twice.
Madrid are aiming to become the first club to retain the Champions League, and take on Bayern Munich for a place in the semi-finals on Wednesday (7.45pm).
They go up against old boss Ancelotti, who was sacked in 2015 after failing to win a trophy that season – even though he had steered the Bernabeu club to their 10th European Cup just 12 months earlier.
And the forward has nothing but praise for his old manager.
“He had a relaxed playing style and was very easy to play under; a very laid-back manager,” he told the Telegraph.
Bale also praised the staff at Real Madrid for how they make sure the players are well-rested for such high-profile clashes.
“There are smaller details like sleep that they have stressed are incredibly important.
“I have always been brought up with the idea that sleep is the best form of recovery. I’ve spoken to a sleep expert and they have told me to always try to go to bed and wake up at a similar time every night and morning.
“Getting this consistency becomes difficult when you’re flying back from away night matches like the game in Munich.”