One of the heterodox sects which branched off from the Theravāda in Sri Lanka (Mhv.v.13).
They formed a part of the Dhammaruci, and separated from that body three hundred and forty-one years after the establishment of Buddhism in Sri Lanka. They lived at first in the Dakkhiṇa-vihāra, but later went to the Jetavana-vihāra, built by Mahāsena. They made certain alterations in the Ubhato-vibhaṅga (MT.175, 176; Cf. Sās.p.24; see also Mhv.xxxvii.32 ﬀ., and MT.680).
According to the Singhalese Nikāyasaṅgrahaya (Quoted in Geiger’s Dīpavaṃsa and Mahāvaṃsa, p.90), the Sāgalikā took their name from their leader, Sāgala Thera, and their separation took place seven hundred and ninety-five years after the Buddha’s death, in the reign of King Gothābhaya. Moggallāna I gave the vihāras of Dalha and Dāṭhākoṇḍañña, on Sīhagiri, to the Dhammarucikas and the Sāgalikā, while he also gave the Rājinī nunnery for the use of the nuns of the Sāgalikā sect (Cv.xxxix.41, 43). Aggabodhi II gave the Veḷuvana-vihāra, which he had built, to the Sāgalikā (Cv.xlii.43). Kassapa IV built for them the Kassapasena-vihāra. Cv.lii.17.