The Seibu Lions Reserves are a professional baseball team based in Tokorozawa, Saitama, Japan. They are the reserve team of the Seibu Lions, one of the most successful teams in the Nippon Professional Baseball (NPB) league. The Seibu Lions Reserves were established in 2004 and play in the Western League, which is the minor league of the NPB.

The team is made up of young and talented players who are looking to develop their skills and gain experience before being promoted to the Seibu Lions' main team. The Seibu Lions Reserves play their home games at the Seibu Dome, which is also the home stadium of the Seibu Lions.

The Seibu Lions Reserves have a strong focus on player development and have produced many successful players who have gone on to play for the Seibu Lions and other NPB teams. The team is known for its strong pitching and solid defense, which are key components of their success.

Overall, the Seibu Lions Reserves are a talented and promising team that is dedicated to developing the next generation of baseball stars in Japan.