Los Angeles International Airport: For Beverly Hills, a rideshare or taxi is usually the actually good choice: roughly 30–50 minutes outside peak traffic, but 60–90 minutes at rush hour; expect about $45–90 before tip/surge. Use the airport’s designated app-pickup instructions rather than accepting unsolicited drivers. The budget alternative is FlyAway to Union Station, then Metro B Line to 7th Street/Metro Center, Metro D Line to Wilshire/Western, and the westbound 720 on Wilshire; allow 1 hour 45 minutes to 2 hours 15 minutes and roughly $15 total. It is cheap, not convenient with luggage.
Hollywood Burbank Airport: BUR is closer in mileage but not reliably quicker once traffic is considered. Rideshare/taxi to central Beverly Hills is about 35–60 minutes, often longer in weekday peaks, and roughly $40–80. On public transport, use the Burbank Airport–North station for Metrolink’s Ventura County Line to Los Angeles Union Station, then Metro B + D and the 720 bus; it is a 1 hour 40 minute-plus trip and makes sense only if you are travelling light.
Los Angeles Union Station: There is no rail station in Beverly Hills. Take Metro B Line from Union Station to 7th Street/Metro Center, transfer to the D Line for Wilshire/Western, then take the westbound 720 along Wilshire into Beverly Hills. Allow about 60–80 minutes; Metro’s base fare is roughly $1.75 with the transfer window. A rideshare is commonly 25–50 minutes and about $25–55, but can be far worse in traffic.