Aleksa Simić (Boljevci, March 18, 1800 – Belgrade, March 17, 1872) was a Serbian politician and one of strongest of the Ustavobranioci, known as the Defenders of the Constitution. His older brother, Stojan Simić, was also a politician and a businessman. Both brothers owed to Miloš Obrenović their rise from humble beginnings to great wealth and power.
Aleksa first came to the Principality of Serbia from Srem, then a Habsburg-occupied territory, in 1819. He was hired as a clerk in the office of Prince Milos Obrenovic. In 1835, Simić becomes the Minister of Finance, and in 1842 he served as Prince Miloš's diplomatic envoy in negotiations with the Ottomans at Constantinople. In 1843 he becomes the Minister of Foreign Affairs of the Principality of Serbia.
His nephew was Đorđe Simić, who held the post of Prime Minister of Serbia.