Count Johan August Meijerfeldt (4 May 1725–21 April 1800) was a Swedish field marshal. To distinguish him from his father, Johan August Meijerfeldt the Elder, he is generally referred to as Johan August Meijerfeldt the Younger. He pursued a military career both outside Sweden, and as an officer in Swedish service in the Pomeranian War and the Russo-Swedish War. Towards the end of the latter war, he was given command of all Swedish land forces in Finland, and promoted to field marshal at the end of the war. He was married to Louise Meijerfeldt.