Mercer Street is a major east–west thoroughfare in the Lower Queen Anne and South Lake Union neighborhoods of Seattle, Washington.

It travels 2 miles (3.2 km) and connects Elliott Avenue to the west and Interstate 5 to the east, serving as one of several downtown exits on the freeway.

[13] During construction of Mercer Street's interchange with Interstate 5 in the 1960s, a tooth belonging to a Woolly mammoth was found by a bulldozer operator.

[14] In the 2010s, the Seattle Department of Transportation embarked on a $190.5 million project to widen and improve Mercer Street, which would be restored to bi-directional traffic between Aurora Avenue and Interstate 5.

[19] On April 27, 2019, a construction crane collapsed onto Mercer Street near its intersection of Fairview Avenue, crushing several cars in the eastbound lanes.