The title compound, C(21)H(21)NO, consists of a carbazole skeleton with a meth-oxy-benzene ring fused to the carbazole, and a butyl group attached to the carbazole N atom. The carbazole skeleton is nearly planar [maximum deviation = 0.078 (2) Å], and it is oriented at a dihedral angle of 4.22 (4)° with respect to the adjacent meth-oxy-benzene ring.