The businessman has had a frayed relationship with Toon fans after his takeover in 2007, but Redknapp believes that he should be given some credit for his financial input at the club.
"To be honest the chairman has had some grief up there and he's put millions and millions of pounds in to the club," he said, speaking ahead of the two sides' encounter at St James's Park.
"Alan Pardew has done a great job as manager. They look a strong outfit at the moment.
"(Pardew's predecessor) Chris (Hughton) went up there and did well, got them promoted. The chairman's spent fortunes up there and they're still shouting and moaning. He's spent about £100m and they're still calling him names."
Spurs go into the match in sixth place in the Premier League table, while Newcastle sit in fourth.