Musk, the billionaire Tesla CEO who has become perhaps US President Donald Trump's most influential adviser, spoke about his crusade to cut government spending and downsize the federal workforce with the administration's Department of Government Efficiency.
The entrepreneur was first announced earlier that day as a speaker, drawing huge cheers from activists at the Conservative Political Action Conference outside Washington, DC.
Before his appearance on Thursday, he met Argentine President Javier Milei, who has been praised by Musk and popularised the power tool while campaigning in 2023 and proposing to slash public spending.
After Musk appeared on stage, wearing shades and his trademark black "Make America Great Again" hat, he said Milei had a gift for him.
The Argentine leader then walked onstage with the red chainsaw and passed it to Musk.
The chainsaw was engraved with Milei's slogan, "Viva la libertad, carajo", which is Spanish for "Long live liberty, damn it".
"This is the chainsaw for bureaucracy," he said.
Musk slammed the previous Biden administration for its immigration policies, specifically naming an app that was used by nearly one million people to be allowed into the US on two-year permits with eligibility to work.
He accused Biden and Democrats of doing that as an "investment" to get more support in swing states.
"A lot of people don't quite appreciate that this was an actual real scam at scale to tilt the scales of democracy in America," Musk said before Newsmax host Rob Schmitt asked him, "Treason?"
Musk responded, "Treason."
When Schmitt asked him if he would consider auditing the Federal Reserve, Musk responded, "Yeah, sure, while we're at it.
"Waste is pretty much everywhere."
When asked to describe inside his mind, Musk replied: "My mind is a storm. It's a storm."
Steve Bannon, a popular Trump ally, followed Musk's appearance and acknowledged he was not the evening's top attraction.
"How did I draw the card to follow Elon Musk?" Bannon asked about a man he has frequently criticised as insufficiently loyal to Trump.
"C'mon man! You bring out the world's wealthiest guy, Superman. I'm supposed to follow it? I'm just a crazy Irishman!"