Demas Hubbard Jr. (January 17, 1806 – September 2, 1873) was a U.S. Representative from New York.

Hubbard was born in Winfield, New York on January 17, 1806, the son of Demas Hubbard and Fanny (Cutler) Hubbard.^[1][2] He attended the public schools and became a farmer. In 1829 he was elected Overseer of Highways for the Village of Smyrna. From 1831 to 1832 he was Smyrna's Village Clerk. He studied law, was admitted to the bar, and commenced practice in Smyrna, New York, in 1835.^[2]

A Whig at the start of his career, Hubbard served as a member of the New York State Assembly from 1838 to 1840.^[2] He became a Republican when the party was organized in the 1850s. He was Smyrna's Town Supervisor from 1859 to 1864, and also served as Chairman of the Chenango County Board of Supervisors.^[2] From 1862 to 1863 he served as President of the Village of Smyrna.

Hubbard was elected as a Republican to the 39th Congress (March 4, 1865 – March 3, 1867).^[2] He was not a candidate for re-nomination in 1866 and returned to practicing law.^[2]

He died in Smyrna on September 2, 1873.^[2] He was buried at Smyrna East Cemetery.^[2]

Hubbard's first wife was Laura Catlin, who died in 1830.^[1] His second wife was Caroline Franklin, who died in 1873.^[1] With his first wife, Hubbard was the father of Alvin C. Hubbard (1829–1867).^[3] With his second wife, he was the father of Abigail Laura Hubbard (1830–1880) and Franklin Hubbard (1832–1853).^[3]