Scituate is considered a South Shore community, located just south of the mouth of greater Boston Harbor. The town is not contiguous; Humarock is a part of Scituate which can only be reached from Marshfield. The latter was formerly connected to the town, but that connection was lost with a river shift as the result of the Portland Gale of 1898. The town's shore varies, with the south (along the mouth of the North River) being marshy, the middle (around Scituate Harbor) being more bucolic, to the rocky coast of Scituate Neck (Minot) in the north. It is off these rocks that Minot's Ledge lies, home to the town's most famous lighthouse. The inland of the town is mostly wooded, with several brooks and rivers (including Cold Brook, for which the town is named) running through.
The town has no freeways running through it; Route 3 runs through neighboring Norwell. Route 3A runs through the town, and is known as Chief Justice Cushing Highway for this stretch, named for Chief Justice William Cushing (1732-1810). The only other state highway in town is Route 123, which terminates at Route 3A, just 0.7 miles from the town line.
There is no air service in town; the closest regional airport is Marshfield Municipal Airport, and the closest national and international air service is at Logan International Airport in Boston.