Is UCLA more selective than UC Irvine for undergraduate admission?

Yes. For general undergraduate admission, UCLA is more selective than UC Irvine overall. Both are competitive UC campuses, but UCLA draws a larger volume of applicants, has a more nationally visible applicant pool, and is typically harder to get into across the board.

That said, UC Irvine is still a selective school and not a fallback in any simple sense. A student who is competitive for Irvine is not automatically competitive for UCLA, especially because UCLA tends to attract more applicants with very strong grades, rigorous coursework, and standout extracurricular profiles.

If you are comparing them from an admissions difficulty standpoint alone, UCLA sits a tier above Irvine. In practice, that means an applicant might be admitted to Irvine and denied by UCLA without that result being surprising.

One important caveat is that selectivity can vary by major. Even though you asked about overall admission, some Irvine programs can be quite competitive, and certain high-demand majors at either campus may narrow the gap somewhat. But looking at the universities as a whole, UCLA is the tougher admit.

From a student-fit perspective, Irvine often appeals to students who want a strong UC education in a somewhat more structured, lower-key environment, while UCLA attracts many students who are comfortable aiming at one of the most competitive public universities in the country. That difference in applicant pool is part of why UCLA is more selective overall.