Does Nintendo Own Final Fantasy? No—Square Enix Does

No. Square Enix (formerly Square Co., then Square Enix after 2003 merger) owns, develops, and publishes the Final Fantasy franchise. Nintendo has never owned the IP.

Several Final Fantasy games have appeared on Nintendo consoles over the decades:

• NES: FFI, FFII, FFIII (Japan only originally)
• SNES: FFIV, FFV, FFVI (as FFII, FFIII in US)
• Game Boy Advance: FFI&II, FFIV, FFV, FFVI (ports)
• Nintendo DS: FFIII, FFIV, FFXII: Revenant Wings (3D remakes)
• 3DS: FF Explorers, World of Final Fantasy
• Switch: FFVII–XV (ports), FF Crystal Chronicles Remastered, Stranger of Paradise

Platform appearances ≠ ownership. Square Enix decides where Final Fantasy goes.