Elon Musk took the witness stand in his “pedo guy” defamation lawsuit trial Tuesday — telling a jury he’s not very influential.

The billionaire tech executive is being sued for $75,000 by British diver Vernon Unsworth after he called the man a “pedo” amid the dramatic rescue of boys from a flooded Thailand cave in 2018.

During his testimony in a Los Angeles court, Musk downplayed his tweet and suggested he wasn’t powerful enough to change public opinion because his foray into climate activism had fallen flat, CNBC reported.

“I’m not sure to the degree I’m influential,” the Tesla founder said when quizzed by Unsworth’s lawyer, the outlet reported. “I have asked people to take climate change seriously … and I haven’t been successful.”

The 48-year-old entrepreneur also defended the ill-advised comment, which Unsworth’s lawyer said had destroyed his client’s life and reputation.

“There are a lot of things I say, and not all of them have the same quality of thought … not everything can be thoughtful,” Musk said.

The spat between the pair began after Musk offered a submarine from his SpaceX rocket company to help with the cave rescue in July 2018.

But Unsworth told CNN after the rescue that the offer was a “PR stunt” and said Musk could “stick his submarine where it hurts.”

Musk then took to Twitter and blasted Unsworth in a series of tweets, including calling him “pedo guy.”

He has since apologized, deleted the tweet, and claimed “pedo guy” was a common insult in South Africa where he grew up that didn’t mean “pedophile.”

The trial, which began Tuesday, is slated to last about five days.

With Post wires