Rollin Samuel Williamson (May 23, 1839 – August 11, 1889) was an American politician, jurist, and telegraph operator from Vermont.

After learning the telegraph trade in Boston, Massachusetts, Williamson moved to Illinois in 1857.

He was appointed operator and station agent in Palatine, Illinois, and studied law in his free time.

In 1880, he was elected judge of the Superior Court of Cook County, where he served a six-year term.

[2] In June 1889, Williamson had a mental breakdown; he had been subject to mood disorders for several years prior.