Robert McKnight was a Republican United States Representative from Pennsylvania.
Mcknight, Robert was born on January 20, 1820 in Pittsburgh.
He attended the common schools and a private school at Xenia, Ohio. He graduated from Princeton College in 1839. He studied law, was admitted to the bar in 1842 and entered into a partnership with Henry S. Magraw in Pittsburgh.
McKnight was hired to be a solicitor for the Bank of Pittsburgh in 1846. He was a city councilman from 1847 to 1849. McKnight was elected as a Republican to the Thirty-sixth and Thirty-seventh Congresses.
He served his district during the American Civil War. After his final term in 1863, he resumed the practice of his profession and died in Pittsburgh in 1885. Interment was in Allegheny Cemetery.