Omiya Ardija (大宮アルディージャ,Ōmiya Arudīja) is a professional association football club based in Ōmiya in Saitama, Japan. Its "hometown" as designated by the league is the whole of Saitama city, which is shared with neighbours Urawa Red Diamonds. Omiya competed in the J1 League following an immediate promotion in 2015 after being relegated in 2014. Omiya was relegated again following the 2017 season. They competed in J1 2005 and continued to remain until 2014, following promotion from J2 in 2004 as the second placed team. The team currently competes in the J2 League.
In 2005–2007 most of Omiya's home matches were held at Saitama Stadium 2002 and Urawa Komaba Stadium due to expansion works at their home ground. In October 2007 the expansion was complete. On November 11, the re-opening match was held as a J. League season match between the Ardija and Ōita Trinita (1–2).