Disclosed are a liquid crystal alignment agent, a liquid crystal alignment film manufactured using the same, and a liquid crystal display including the liquid crystal alignment film. The liquid crystal alignment agent includes a polymer comprising a polyamic acid including a repeating unit represented by Chemical Formula 1, polyimide including a repeating unit represented by Chemical Formula 2, or a combination thereof: wherein Y1 and Y2 are each independently a divalent organic group derived from diamine, wherein the diamine includes photodiamine represented by Chemical Formula 3 and functional diamine represented by Chemical Formula 5: and wherein the other substituents are the same as defined in the detailed description.