The following is a list of Santa Clara Valley Transportation Authority bus routes. Route numbers are classified as follows:
- Lines 1-99 are standard local bus routes, which feature many, closely spaced stops. These lines serve a smaller area, such as connecting transit centers to the surrounding community or Downtown San Jose to nearby neighborhoods.
- Lines 100-199 are express services and primarily operate during peak periods only. These lines operate express mainly on freeways and provide fewer stops than local services, mainly at train stations and major transfer points in Santa Clara County. These also charge higher fares than standard bus routes.
- Lines 200-299 are school services that operate limited service to several area high schools.
- Lines 500-599 are limited stop "Rapid" branded routes.
- Lines 800-899 are commuter rail shuttles that operate mainly during peak periods. These lines operate of Great America ACE/Amtrak Station and serve nearby high-tech businesses and industrial parks.
- Lines 900-999 are intercity routes operated in conjunction with other agencies.
VTA embarked on a large network redesign that was implemented on December 28, 2019. This eliminated the DASH shuttle, Almaden Light Rail shuttle, limited-branded bus service, community bus service, and many express routes but established a core frequent network and increased service on numerous local bus routes.
In 2023, VTA's bus system had a ridership of 21,419,200, or about 71,600 per weekday as of the first quarter of 2024.