Montedio Yamagata were founded in 1984 in Tsuruoka, Yamagata Prefecture, as the NEC Yamagata Soccer Club, a company team rooted in the Tohoku region of northern Japan. After winning four consecutive Tohoku regional league titles between 1990 and 1993, the club earned promotion to the Japan Football League in 1994. A rebrand in 1996 gave the club its current name — Montedio, a coined word blending the Italian for mountain (Monte) and God (Dio), a nod to the mountainous landscape of Yamagata. When the J.League's two-division structure launched in 1999, Montedio entered as a founding J2 member.
The club's most celebrated era came under manager Shinji Kobayashi. After years of building in J2, Montedio secured promotion to J1 for the first time in November 2008, finishing second in the division. They went on to achieve their highest-ever J1 finish of 13th place in 2010. Relegation followed in 2011, partly due to the withdrawal of key loan players and a disrupted season in the wake of the Great East Japan Earthquake. A second stint in J1 was earned via the promotion playoff final in 2014, though the club returned to J2 after just one season.
Since then, Montedio have been a consistent presence in J2, competing in their tenth consecutive season at that level in 2025. Their defining regional rivalry is the Dewa Derby — now formally styled the Ōu Honsen — contested against TDK SC (later Blaublitz Akita), a fixture that dates to 1990 and is named after the JR Ōu Main Line that connects the former Dewa Province. The club plays home matches at ND Soft Stadium Yamagata in Tendō.