Jesse Monroe Knowles (July 23, 1919 – April 23, 2006) was a businessman, civic leader, and politician, elected as a Democratic Party member to both houses of the Louisiana State Legislature for Calcasieu Parish. He served a total of twenty years in both chambers. From the late 1960s, the Republican Party had been attracting white southern conservatives into its ranks. In the last weeks of his last term as state senator in 1980, Knowles switched to the GOP. He had supported Republican David C. Treen for governor of Louisiana in 1979 and was appointed to state posts.