Route 148 is a 19.68-mile-long (31.67 km) south–north state highway in central Massachusetts.

It travels entirely in Worcester County.

Route 148 begins at US 20 in Fiskdale, a village in Sturbridge.

The highway runs north under Interstate 90 (the Massachusetts Turnpike) without an interchange and past the Tantasqua Regional High School before entering Brookfield, where there is a very brief concurrency with Route 9 in the center of the town.

After the two highways diverge, Route 148 passes through the southeastern corner of New Braintree for less than one-half-mile (0.80 km) and then enters Oakham, where the highway ends at Route 122.