The Russian business tycoon bought the Blues in 2003.
And Gallas, who spent five years at Chelsea from 2001 - 2006, says Abramovich was a hands-on owner.
He told Four Four Two magazine: “When we won games, he would often come in the changing room and speak to some of the players.
“He was like, ‘How are you? I’ve seen you receiving some kicks, do you think you will be all right to play in the next match?’
“He was really close to us all.”
Gallas quit Chelsea for Arsenal in 2006 with Ashley Cole heading in the other direction.
The former French international says he didn't know what to expect when making the move across London - but the Arsenal fans did surprise him.
He added: "I would say that my best memory at Arsenal is actually my first game against Middlesbrough.
“Because I’d arrived from Chelsea, the supporters would normally boo you.
“But when I was out on the pitch during the warm-up, they all applauded me. That was really nice – I did not expect that.”
Gallas also went on to play for Tottenham after a four-year stint at the Emirates.
He retired in 2014 having spent the final year of his career at Australian side Perth Glory.
