Paul, who continues to push forward with his fledgling campaign, got a rousing welcome at the Westwood campus. More than 5,000 people filled Straus Stadium. The overflow crowd could be seen outside climbing trees to get a listen.
The 12-term Texas congressman stuck to his message about threats to financial freedom and his call to end big government and the war.
"In the last 10 years there was $4 trillion added to our national debt due to the wars going on in the Middle East. I want to end those wars, end them quickly. We just marched in, let's just march home," Paul said.
Paul isn't the only one pledging he's in the race until the end. Rick Santorum took his campaign to the bowling alley Wednesday night despite losing a string of primaries Tuesday.
Perennial frontrunner Mitt Romney turned his attention from his GOP rivals to President Barack Obama, launching a battle over who's more out of touch.
Paul has yet to win a primary this campaign season, but his anti-war message often resonates with students.
"His ideas, while aren't universally liked, unfortunately, are the only genuine and passionate views that would really change America," said UCLA student Eli Mordecai.
Also during his California visit, Paul will visit UC Berkeley and hold a fundraiser in San Francisco on Thursday.
His Republican rivals also made recent stops in California, which holds its primary June 5.
The Associated Press contributed to this report.