克尔白或称卡巴天房、天房等（阿拉伯语：الكعبة‎，罗马化：al-Kaʿbah），是一座立方体的建筑物，意即“立方体”，位于伊斯兰教圣城麦加的禁寺内。相传是第一个人类阿丹（亚当）兴建的，并由易卜拉欣（亚伯拉罕）和易斯马仪（以实玛利）父子共同修建的。伊斯兰传统认为克尔白是天堂的建筑“天使崇拜真主之处”（阿拉伯语：البيت المعمور‎，罗马化：al-Baytu l-Maˤmur）在地上的翻版，而克尔白的位置就直接在彼天堂建筑之下。《古兰经》记载：“为世人而创设的最古的清真寺，确是在麦加的那所吉祥的天房、全世界的向导。”

The kabah (Arabic:الكعبة‎‎ al-Kaʿbah IPA: [alˈkaʕba], "The Cube") also referred as Kaaba Muazzama (Grand Kaaba), is a building at the center of Islam's most sacred mosque, Al-Masjid al-Haram, in Mecca, al-Hejaz, Saudi Arabia. It is the most sacred Muslim site in the world. It is considered the "House of God" and has a similar role to the Tabernacle and Holy of Holies in Judaism. Wherever they are in the world, Muslims are expected to face the Kaaba when performing salat (prayer). From any point in the world, the direction facing the Kaaba is called the qibla.