Johann Nepomuk Karl, Prince of Liechtenstein (Johann Nepomuk Karl Borromäus Josef Franz de Paula) was the Prince of Liechtenstein between 1732 and 1748. He was the son of Johann Josef Adam.
When his father died, Johann Nepomuk Karl was only eight and his uncle Josef Wenzel ruled as regent and took care of his nephew's education, preparing him for his future role. When Johann Nepomuk Karl took over the rule of his domains alone in 1745, it seemed that his uncle had taught him nothing, because the prince soon neglected the government and otherwise had seen little economic success.
Because of the evident inability of the prince, a royal Hungarian and Bohemian royal chamberlain was appointed to rule. The prince died shortly afterwards in 1748 at Wischau aged 24 years, being the youngest Prince of Liechtenstein to die.