Clement Hall Sinnickson (September 16, 1834 – July 24, 1919), was an American Republican Party politician, who served in the United States House of Representatives, where he represented New Jersey's 1st congressional district from 1875 to 1879.

Born in Salem, New Jersey, he attended private schools, and the Rensselaer Polytechnic Institute, before graduating from Union College, New York, in 1855.

During the Civil War Sinnickson served as Captain in the Union Army.

He also served as a delegate to the 1880 Republican National Convention, and he was appointed judge of the Court of Common Pleas in 1896 and reappointed in 1901 and 1906.

Sinnickson died in Salem, New Jersey on July 24, 1919, and was interred at St. John's Episcopal Cemetery.