Robert Ballard Gilliam (1805–1870) was a North Carolina politician and judge.
Gilliam graduated from the University of North Carolina at Chapel Hill in 1823, in the same class with future state Treasurer Daniel W. Courts, future Chief Justice Richmond M. Pearson, and others.
Gilliam was also a member of the 1835 convention that thoroughly revised the Constitution of North Carolina.
Gilliam was elected to represent Granville County in the North Carolina General Assembly House of Commons in 1836, 1838, 1840, 1846, 1848 and 1862.
John H. Wheeler wrote of Gilliam, "As a statesman, he was a pure and patriotic; as a lawyer, he was learned and able, and his ability was only equalled by the kindly qualities of his heart.