A problem addressed by the present invention is to provide a polymer having high hole injection/transport capacity and high durability and a composition for an organic electroluminescence element including the polymer. Another problem addressed is to provide an organic electroluminescence element having high brightness and long service life. Another problem addressed is to provide an organic electroluminescence element having low drive voltage and long life. A polymer including a repeating unit represented by formula (1). In the formula, G represents an optionally substituted aromatic hydrocarbon group, an optionally substituted aromatic heterocyclic group, or a C atom, N atom, B atom, or P atom, Ar2-Ar4 each independently represent an optionally substituted divalent aromatic hydrocarbon group, an optionally substituted aromatic heterocyclic group, or a divalent group in which a plurality of optionally substituted aromatic hydrocarbon groups or optionally substituted aromatic heterocyclic groups are linked directly or via linking groups, Ar5 represents an optionally substituted aromatic hydrocarbon group, an optionally substituted aromatic heterocyclic group, or a monovalent group in which a plurality of groups selected from optionally substituted aromatic hydrocarbon groups and optionally substituted aromatic heterocyclic groups are linked directly or via linking groups, and Ar6 represents a hydrogen atom or a substituent. "-*" in Ar1 is the bonding position with G in formula (1).