Provided are: a lubricant base oil capable of achieving both a high traction coefficient and an excellent low-temperature fluidity at a higher level and having a high flash point, which contains a ring-containing compound having at least (i) a crosslinked bicyclic ring where two rings are bonded while sharing 3 or more carbon atoms, and (ii) an acyloxy group or a hydrocarbyloxycarbonyl group each containing a branched hydrocarbon group with a main chain having 4 or more carbon atoms, a lubricating oil composition containing the lubricant base oil, and a continuously variable transmission using the lubricating oil composition.