巴西利卡（拉丁语：Basilica，希腊语：Βασιλική）是古罗马的一种公共建筑形式，其特点是平面呈长方形，外侧有一圈柱廊，主入口在长边，短边有耳室，采用条形拱券作屋顶。后来的教堂建筑即源于巴西利卡，但是主入口改在了短边。

巴西利卡这个词来源于希腊语，原意是“王者之厅”的意思，拉丁语的全名是basilica domus。本来是大都市里作为法庭或者大商场的豪华建筑。

基督教沿用了罗马巴西利卡的建筑布局来建造教堂，尤其罗马风时代的大多数教堂是巴西利卡格局。随着历史的变迁，巴西利卡这个词的意义也发生了变化。今天在天主教中，有特殊地位的教堂被赋予「宗座圣殿」的头衔；宗座圣殿的拉丁语即与巴西利卡同字，不论其建筑风格和结构。

The Latin word basilica (derived from Greek βασιλικὴ στοά, Royal Stoa, the tribunal chamber of a king) has three distinct applications in modern English. The word was originally used to describe an ancient Roman public building where courts were held, as well as serving other official and public functions. To a large extent these were the town halls of ancient Roman life. The basilica was centrally located in every Roman town, usually adjacent to the main forum. These buildings, an example of which is the Basilica Ulpia, were rectangular, and often had a central nave and aisles, usually with a slightly raised platform and an apse at each of the two ends, adorned with a statue perhaps of the emperor, while the entrances were from the long sides.