Seyyed Mohammad Hassan Hosseini Quchani (Persian: سید محمد حسن حسینی قوچانی), known as Aqa Najafi Quchani (Persian: آقا نجفی قوچانی) was one of the Islamic scholars and jurists of the fourteenth century AH. He was one of the disciples of Muhammad Kadhim Khorasani and reached the degree of ijtihad at the age of 30. Aqa Najafi Quchani wrote the famous books Siahat-e Gharb and Siahat-e Shargh.