The entry 'Kasagi-dera Temple Hakko (eight lectures) was began' in the "Todai-ji Yoroku" (Todai-ji Temple Records) entry for the year 879 is the first written reference to Kasagi-dera Temple but the actual founding is thought to have taken place during the Nara period.
『東大寺要録』元慶元年（879年）条に「笠置寺八講始行」とあるのが笠置寺の文献上の初見であるが、実際の創建は奈良時代にさかのぼるものと思われる。