Kopperl (pronounced KOP-er-ul) is an unincorporated community in Bosque County, Texas, United States. It lies on the northwestern end of Lake Whitney, and has an estimated population of 225.
Kopperl was founded in 1881. Named after Galveston banker and railroad tycoon Moritz Kopperl, the town was established as a regional shipping point along the Gulf, Colorado and Santa Fe Railway. The population peaked at 329 in 1904 before declining to 225 by the 1970s, a figure it has maintained fairly consistently since.