Arsenal's eight-year trophy drought looks set to continue after they suffered a 3-1 defeat to Bayern Munich in the first leg of their Champions League second round match on Tuesday night.
The Gunners sit fifth in the Premier League and Wenger's popularity with Arsenal fans has also been dented by FA Cup and League Cup exits after defeats to Blackburn and Bradford respectively.
But Garde - the first man the Gunners boss signed for the club in 1996 - believes his compatriot is not being judged fairly after his years of hard work at Arsenal.
"I think that Arsene Wenger is still a top-class manager," Garde said ahead of Lyon's Europa League last 32 second leg clash against Tottenham at the Stade de Gerland.
"He has spent so many years at this club, he has brought so much to this club.
"I can testify because I used to be one of his players. He brought so much to the club, even if he didn't win so many trophies.
"I think he deserves more respect than what he is getting at the moment. Of course we know football is a business that is judged on results, but I think he deserves more respect and he is still a world-class manager."
Tottenham hold a 2-1 first-leg lead over Lyon after two superb goals from Gareth Bale at White Hart Lane, but Garde feels Samuel Umtiti's thunderbolt strike for his side could prove crucial on Thursday night.
"We know the away goal is very important," he said.
"We need to be patient. We have 90 minutes to qualify. It will be difficult but we can try to close them down and try to cut out their speed.
"To be able to qualify in front of the home fans would be exciting. We won (4-0 against Bordeaux) last weekend so we have a better mentality now."