Stepan Meliksetovich Aghajanian (Armenian: Ստեփան Մելիքսեթի Աղաջանյան; 16 December 1863 – 13 December 1940) was an Armenian painter; known primarily for portraits and landscapes.
He was born in Shusha. His father was a tailor. He began his education at the (1872–1881), then transferred to the local Russian school (1881–1884). Following that, he moved to Baku then, in 1886, left to study in France.
He initially studied art in Marseille (1886–1890). Later, he went to Paris, where he entered the Académie Julian. He was there from 1897 to 1900, studying with Jean-Paul Laurens and Jean-Joseph Benjamin-Constant.
In 1900, he returned to Shusha, then worked in Baku from 1902 to 1904. Finally, he settled in Rostov-on-Don, where he taught painting in the public schools until 1921.
He returned to Armenia in 1921, at the beginning of the Russian Civil War. After 1929, he worked as a teacher at the Art Industrial College (now the ]). He was awarded the title of People's Artist of the Armenian SSR. The following year, he was presented with the Order of the Red Banner of Labour. He died in 1940 in Yerevan.