Clarence Don Clark (April 16, 1851 – November 18, 1930) was an American teacher, lawyer, and politician from New York.

He participated in the constitutional convention for Wyoming's statehood and was that state's first congressman.

[2] In 1889, he began his political career as a delegate to the Wyoming constitutional convention.

[1] After losing the election in 1916, he resumed the practice of law in Washington, D.C., but was appointed as a member of the International Joint Commission in 1919.

Clark died on November 18, 1930, and is interred at the Masonic Cemetery in Evanston.