Daniel Clark (October 24, 1809 - January 2, 1891) was an American politician who served in the New Hampshire legislature and the United States Senate.
Clark was born in Stratham, New Hampshire. He attended common schools, Hampton Academy, Union College, and graduated Dartmouth College in 1834. He studied law and was admitted to the bar in 1837 and practiced in Epping, New Hampshire from 1837-1839 and then moved to Manchester.
He was elected to the state legislature from 1842-1843, 1846, and 1854-1855. He was elected to fill James Bell's seat in the US Senate (Bell died) in 1857, was reelected in 1861, serving from June 27, 1857 to July 27, 1866 (he resigned). During his tenure in the Senate he served as President pro tem in the 38th Congress and on the Claims Committee from the 37th Congress to 39th Congress.
After resigning from the Senate, Clark served as a US District Court Judge from 1866 to his death. He died on January 2, 1891 in Manchester and was buried in Valley Cemetary.