American lawyer and constitutional reformer in Rhode Island who led the Dorr Rebellion (also known as Dorr's Rebellion) in 1842.

As a member of the state legislature (from 1834), Dorr failed in his reform efforts. In 1841 he organized the People's Party, which called a convention, adopted a new constitution, held elections, and, on May 3, 1842, installed Dorr as governor. The preexisting government did not recognize him, and Rhode Island for a time had two administrations. Minor armed clashes occurred. Tried for treason, Dorr was sentenced (1844) to life imprisonment, but he was released a year later.