Carl Friedrich Andreyevich von Jaenisch (Vyborg, April 11, 1813 – Saint Petersburg, March 7, 1872) was a Finnish and Russian chess player and theorist. In Russian, he was known as Яниш (‘Yanish’) although a phonetic translation of the original German name would have been ‘Ениш’. In the 1840s, he was among the top players in the world.