Isaac Herschel Goodnight (January 31, 1849 – July 24, 1901) was a United States representative from Kentucky.

[2] He returned to Franklin, serving as deputy circuit clerk while reading law, and was admitted to the bar in 1874.

[3] In 1877, Goodnight was elected to the Kentucky House of Representatives, serving a single, two-year term.

[2] Due to ill health and the fact that his absence from home was hurting his legal practice, Goodnight did not seek re-election in 1894.

[2] After leaving Congress, he was elected a judge of the seventh Kentucky circuit in 1897 and served until his death in Franklin on July 24, 1901.