Lolei  is the northernmost temple of the Roluos group of three late 9th century Hindu temples at Angkor (others members of which are Preah Ko and the Bakong).

Lolei was the last of the three temples to be built as part of the city of Hariharalaya that once flourished at Roluos, and in 893 the Khmer king Yasovarman I dedicated it to Shiva and to members of the royal family.

The name "Lolei" is thought to be a modern corruption of the ancient name "Hariharalaya," which means "the city of Harihara." Lolei was located on an island slightly north of centre in the now dry Indratataka baray, construction of which had nearly been completed under Yasovarman's father and predecessor Indravarman I. Scholars believe that placing the temple on an island in the middle of a body of water served to identify it symbolically with Mount Meru, home of the gods, which in Hindu mythology is surrounded by the world oceans.

The temple of Lolei, which like the Mebon, occupies an island in the middle of the artificial lake (Baray Indratadaka), only the two tiered pyramid with four of the six towers which had been planned, remain intact. The four towers are, contrary to normal practice and in spite of the fact that the first plan was abandoned, completely finished. Now they are very badly ruined. A sandstone channel in the shape of a cross situated in the centre of the four towers. The channel extend in the cardinal directions from a square pedestal for Linga.