MetroBus is a public bus service operated by Metro Transit that serves the Greater St. Louis area. In 2023, the service had an annual ridership of 12,531,400, or about 39,400 per weekday as of the fourth quarter of 2023.

MetroBus currently operates 59 fixed bus routes in a shared fare system with the MetroLink light rail service. Of its 59 bus routes, 46 of them operate in St. Louis City and County in Missouri with 13 routes in St. Clair County, Illinois.^[3] In September 2019, as part of Metro Reimagined, Metro restructured Missouri bus routes to add increased frequency on busy routes but discontinued six low ridership routes.^[4][5]

In June 2021, Metro introduced the region's first electric buses including 40-foot and 60-foot articulated models. The 60-foot articulated buses are used exclusively on the #70 Grand bus line, the region's busiest.^[6]

Beginning with the COVID-19 pandemic in 2020, MetroBus has seen a sharp decline in ridership and it's estimated that full recovery could take several years.^[7] In addition, ongoing labor shortages have reduced Metro's ability to offer comprehensive service to its riders.^[8][9] In June 2023, weekend service was reduced on 26 routes and suspended on 4 others.^[10] In an effort to recruit more drivers, Bi-State's board signed a contract in August 2023 with Amalgamated Transit Union Local 788, which approved a salary increase for each of the next two fiscal years and a $5,000 signing bonus. However, recruitment remains low and Metro slashed the number of full-time bus driver slots in its 2024 budget by 21%, from 811 to 635.^[9]

In January 2024, after several successful hiring events, Metro announced increased frequency on 17 bus routes in St. Louis City and County. At the time of the service adjustment, driver ranks had increased to 618, up from 556 in November 2023.^[11]

MetroBus operates in a shared fare system with the MetroLink light rail service. When boarding, riders with valid passes present them to the operator. Riders without passes are able to pay exact change into the onboard farebox.^[14]

Metro also accepts some fares from Madison County Transit (MCT) on its services. MCT's 2-hour regional pass is accepted as full fare on MetroBus and its senior/ADA passes qualify as reduced fare on Metro services. In addition, Metro's 2-hour pass/transfer is valid for a single bus trip on MCT with no additional charge.^[15]

Residents called to jury duty in Metro's service area may travel on MetroBus free of charge.^[15]

Metro Transit operates 261 vehicles for MetroBus, including 237 35- and 40-foot low-emission, low-floor diesel buses made by Gillig; 10 electric 40-foot Gillig buses; and 14 electric 60-foot articulated New Flyer XE60 buses. Electric buses are charged overnight at the Brentwood and DeBaliviere garages, while in-service charging is at the North Broadway Transit Center.^[17][18][19]

All MetroBus vehicles are equipped with an accessible lift or ramp and include priority seating.^[20] Additionally, each vehicle is equipped with a two-bike bike rack, available on a first-come, first-served basis.^[21]