And he revealed Spurs came close to signing him last year.
"Apparently they were going to take him, weren't they?" said Redknapp on TalkSPORT.
"The club was in trouble and maybe Daniel Levy thought he could really get him very cheap. Then the new owners came into Villa and they didn't need the money suddenly."
Spurs boss Mauricio Pochettino wants to add more home-grown players to his squad to help meet the quotas for the Premier League and European competitons.
"I love Grealish," added Redknapp. “I think he's a real talent, honestly. I love watching him play.
"I think he's a kid who could play at the very top level."