Happier Than Ever: A Love Letter to Los Angeles is a 2021 American concert film directed by Robert Rodriguez and Patrick Osborne, starring singer-songwriter Billie Eilish. It features performances of all 16 tracks from Eilish's second studio album, Happier Than Ever (2021), at the Hollywood Bowl amphitheater. She is accompanied by other musicians, including her brother Finneas O'Connell and the Los Angeles Philharmonic. Inspired by films such as Who Framed Roger Rabbit (1988) and Cool World (1992), A Love Letter to Los Angeles blends live action and animation.

Besides directing, Osborne worked on the animation in collaboration with Nexus Studios, Zoic Studios, and Digital Frontier FX, mixing motion capture footage with rotoscoping techniques. Filming took place for one week in Los Angeles, mostly at the Hollywood Bowl, without a live audience due to the COVID-19 pandemic. The crew aimed to avoid making the performances feel too similar, so they produced distinct color palettes and lighting effects for every song. They often recorded Eilish from close distances, wanting to create a sense of intimacy between her and the viewers.

A Love Letter to Los Angeles was released exclusively to Disney+ on September 3, 2021. Critics praised its performances—which they felt were of similar or better quality compared to the songs' studio versions—as well as its animation, cinematography, and setting. It received nominations for Best Austin Film at the 2021 Austin Film Critics Association Awards, Best Music Film at the 64th Annual Grammy Awards, and Best Longform Video at the 2022 MTV Video Music Awards.