Prince Carl (Karl) of Solms-Braunfels was a German prince and military officer in both the Austrian army and the cavalry of the Grand Duchy of Hesse. As commissioner general of the Adelsverein, he spearheaded the establishment of colonies of German immigrants in Texas. Prince Solms named New Braunfels, Texas, in honor of his homeland.

Solms-Braunfels was a County and later Principality with Imperial immediacy in what is today the federal Land of Hesse in Germany.