The 1863 United States Senate election in Massachusetts was held on January 9, 1863. Incumbent Charles Sumner was re-elected to a third term in office.

At the time, Massachusetts elected United States senators by a majority vote of each separate house of the Massachusetts General Court: the House and the Senate.

In the 1862 state legislative elections, supporters of the Lincoln administration who nonetheless opposed the emancipation of Southern slaves and Senator Sumner's re-election organized a "People's Convention," hoping to consolidate opposition and gain enough seats in the legislature to deny Sumner election. However, the legislature remained largely Republican, ensuring Sumner's victory in the January election.^[1]

The lone vote for Adams was cast by Senator Whitney of Hampden. Senator Crane of Worcester County did not vote.^[2]