Nintendo Research & Development No. 1 Department, commonly abbreviated as Nintendo R&D1, was Nintendo's oldest video game development team. It was known as Nintendo Research & Development Department before splitting in 1978. Its creation coincided with Nintendo's entry into the video game industry, and the original R&D1 was headed by Gunpei Yokoi. The developer has created several notable Nintendo series such as Metroid, Mario Bros. and Donkey Kong.

R&D1 developed the hugely successful Game Boy line, which was released in 1989. They developed some of the line's most popular games, such as Super Mario Land, and created the character of Wario.

Team Shikamaru was a small club within Nintendo R&D1 that was composed of Makoto Kano, Yoshio Sakamoto, and Toru Osawa. The group was responsible for designing characters and coming up with scripts for several games including Metroid, Kid Icarus, Famicom Detective Club, Trade & Battle: Card Hero, and several others.

After Yokoi's resignation in 1997, this group was led by Takehiro Izushi. In 2004, Satoru Iwata restructured the Nintendo R&D1 team. Many of the staff members were later reassigned to the Nintendo SPD team, which in turn merged with Nintendo EAD in 2015 to form Nintendo Entertainment Planning & Development.