A hair clip includes two hinged clip bodies and an elastic fastener. Each clip body includes a press portion with a through-hole therein. Each clip body further includes a clamp portion extending from the press portion and having a recess in an outer surface thereof. The elastic fastener includes two spaced end portions and a central portion between the end portions. The end portions of the elastic fastener respectively penetrate the through-holes in the press portions of the clip bodies and are engaged in the recesses in the clamp portions for positioning. The elastic fastener has a roughly elliptic cross section which contributes to service life of the hair clip.