The Viscount Palmerston, of the Whigs, first formed a government by popular demand in 1855, after the resignation of the coalition government of Lord Aberdeen. He was heavily criticised by Parliament in 1857 over the conduct of the Second Opium War and called a dissolution, but the nation voiced its support in the resulting general election and he remained in power. In 1858 he resigned when defeated "on a measure for removing conspiracies to murder abroad from the class of misdemeanour to that of felony", and was succeeded by another short-lived Conservative government under Lord Derby.
The first Palmerston ministry lasted from 1855 to 1857, and the second Palmerston ministry from 1857 to 1858.
Members of the Cabinet are indicated by bold face.