Belluna Dome (ベルーナドーム, Berūna Dōmu) (official name: Seibu Dome (西武ドーム, Seibu Dōmu)) is a baseball stadium located in Tokorozawa, Saitama, Japan.

The stadium was built in 1979 without the roof and named Seibu Lions Stadium (西武ライオンズ球場, Seibu Raionzu Kyūjō) as the new home field of the Lions that moved from Fukuoka to Tokorozawa that year.

The naming rights contract with Goodwill was intended to remain in effect for five years.

On January 16, 2017, MetLife, a New York City-based financial institution, purchased naming rights for five years.

[8] Lady Gaga performed two sold-out shows at the stadium for her Chromatica Ball tour on September 3 & 4, 2022.