In 1885, shortly after Fisher County was organized, a dispute arose between business partners from Mississippi and a town called Fisher. Both wanted their land to host the courthouse. The partners were M.L. and D.C. Roby, and the town of Fisher is now called North Roby.
In 1886, construction was begun on the new courthouse and a school and post office opened. The community had thirteen houses by that summer. In 1890 the population was estimated to be 300 people and the town had a hotel, two general stores, Baptist and Methodist churches, a restaurant and a weekly newspaper, the Fisher County Call.
Roby had no jail until 1892, when one was constructed out of stone. A new jail was built in 1926 out of brick, and is still in use as of 2010. It has had three different courthouses during its existence, unlike many Texas county seats which have preserved and restored original courthouses. The most recent courthouse was built in 1972, and is strikingly modern in comparison to those found in many Texas counties.
In 1898 the first bank was chartered and the Roby school district was formed. The area covered by the school district grew slowly over the years as it absorbed rural schools in the vicinity.
By 1900 the population had grown to 712 residents. By 1914 it had Baptist, Methodist, Presbyterian and Nazarene churches. Telephone service was also established as of 1914.
Roby received its first railroad in 1907 (The Texas Central) and in 1915 the Roby and Northern laid 4.4-miles of track to connect Roby proper with North Roby. In 1930 the population was 801. It actually increased during the Great Depression – reaching 904 for the 1940 Census. The Roby and Northern line was scrapped during World War II and its rails went to the war effort.
Forty-two lucky residents of Roby, Texas put $10 each in a lottery pool in 1996 and won the $46,000,000 jackpot on Thanksgiving of that year, making 6-7% percent of the population millionaires instantly.