Service has been disrupted since about 8 p.m. Friday after the sinkhole was discovered near the tracks at the intersection of Judah Street and 29th Avenue, according to spokesman Judson True.
Buses are shuttling passengers on the N-Judah line between 19th Avenue and La Playa Street.
Crews with the San Francisco Public Utilities Commission and the city's Department of Public Works are repairing the sinkhole, according to True.
There is no estimate for when regular service will resume on the line.