Polymer, composition for organic electroluminescent element, organic electroluminescent element, organic el display device, and organic el illumination

Provided are a polymer having high hole injection/transport ability and high durability, a composition for an organic electroluminescent element which includes the polymer, an organic electroluminescent element having high luminous efficiency which is fabricated using the composition, and a display device and illumination device which use the organic electroluminescent element. This polymer contains units represented by formula (1) as repeating units. (In formula (1), Ar 1 , R 1 , and T 1 are each the same as defined in the specification.)