The Nankai Main Line is one of the two main railway lines of Japanese private railway company Nankai Electric Railway, together with Kōya Line. The route is from Namba Station in south downtown of Osaka to Wakayamashi Station in Wakayama via Sakai, Izumiōtsu, Kishiwada, Kaizuka, Izumisano, Sennan, Hannan and Misaki municipalities. The proper name is with the company's name, "the Nankai Main Line", not simply "the Main Line" often seen in other Japanese private railways. Lines of the Nankai Main Lane and the connecting lines excluded the Kōya Line and the Airport Line are named generically "the Nankai Line ". The line is shown with a pictogram of waves, or distinguished with blue from conifer or green Kōya Line.

Namba Station is a name shared by two physically separated railway stations in the Namba district of Chūō-ku, Osaka, Japan, operated by Nankai Electric Railway and the Osaka Metro. The name "Namba Station" can also refer to the entire station complex as a whole, including the similarly named JR Namba Station and Ōsaka Namba Station.