The Microsoft co-founder has slammed the Tesla and SpaceX boss over his "outrageous comments" amid the coronavirus pandemic, including criticising lockdowns, claiming deaths as a result of the respiratory infection have been over-counted and even calling California's response to combatting the virus "fascist".
But Gates believes he shouldn't be commenting about it in case he confuses "areas he's not involved in too much".
In an interview with CNBC's Andrew Ross Sorkin on 'Squawk Box', he said: "Elon's positioning is to maintain a high level of outrageous comments.
"He's not much involved in vaccines. He makes a great electric car. And his rockets work well. So he's allowed to say these things. I hope that he doesn't confuse areas he's not involved in too much."
The tech entrepreneur described the government's policies as "fascist" on Twitter recently.
He wrote: "To say that they cannot leave their house, and they will be arrested if they do, this is fascist. This is not democratic. This is not freedom. Give people back their goddamn freedom. (sic)"
Musk - who welcomed his first child with singer Grimes, a son named X Æ A-XII in May - also suggested the lockdown is an infringement of American values.
He said: "Breaking people's freedoms in ways that are horrible and wrong is not why people came to America or built this country. (sic)"
By contrast, Facebook CEO Mark Zuckerberg has warned against trying to return to normality amid the coronavirus pandemic.
The 36-year-old billionaire dampened down talk of reopening the US economy back in April, suggesting it would be a bad idea for public health and the economy.
He said: "While there are massive societal costs from the current shelter-in-place restrictions, I worry that reopening certain places too quickly before infection rates have been reduced to very minimal levels will almost guarantee future outbreaks and worsen longer-term health and economic outcomes."