The iconic singer criticised the Chanel fashion house boss for his recent interview, where he said Adele was a little "too fat" to be a model.
Asked about Lagerfeld's comments, Madonna told The Sun: "That's horrible. That's ridiculous, that's just the most ridiculous thing I've ever heard.
"I don't like it when anybody says anything bad about anyone - I don't like it. Adele's a great talent and how much she weighs has nothing to do with it."
Madonna continued: "The thing for Adele to remember is at the end of the day, whether you rise or fall, it has so much to do with how you sustain yourself and keep your integrity and your inner strength.
"It is all about who you surround yourself with - friends and people who really do care about you, and care about your well-being beyond being a superstar. That's the most important thing."
Madonna will release 'Girl Gone Wild' as the second single from her upcoming album MDNA, which will be released worldwide on March 26.
> Madonna gets chained up in 'Girl Gone Wild' video teaser: Watch now
Listen to Madonna's 'Girl Gone Wild' below: