"The potential was always there with Leighton when I was with him at Wigan. He has just gone on and shown what a good player he is," Kilbane told the club's official website.
"When he first came to Everton he didn't really play for a while, he was in and out of the team. But since he has got into the side he has had a really good run at it.
"He is amongst the best in the country and he is probably England's best left-back now. I firmly believe that."
Baines has made 28 appearances for the Toffees this season in all competitions, scoring six goals.