This paper deals with the study of the two-dimensional Dirac operator with infinite mass boundary condition in a sector. We investigate the question of self-adjointness depending on the aperture of the sector: when the sector is convex it is self-adjoint on a usual Sobolev space whereas when the sector is non-convex it has a family of self-adjoint extensions parametrized by a complex number of the unit circle. As a byproduct of this analysis we are able to give self-adjointness results on polygones. We also discuss the question of distinguished self-adjoint extensions and study basic spectral properties of the operator in the sector.