A liquid crystal alignment agent capable of forming a liquid crystal display element having good resistance to ultraviolet decay and no mura effect, a liquid crystal alignment film, and a liquid crystal display element having the same are provided. The liquid crystal alignment agent includes a polymer (A), a polysiloxane (B), a polymerizable compound (C) containing a benzophenone structure, and a solvent (D). The polymer (A) is obtained by reacting a mixture. The mixture includes a tetracarboxylic dianhydride component (a1) and a diamine component (a2). The polysiloxane (B) contains a polymerizable unsaturated group, wherein the polymerizable unsaturated group includes a group represented by formula (1-1), a group represented by formula (1-2), or a combination of the two.