We present a self-dual N=1 supersymmetric Dirac-Born-Infeld action in three
dimensions. This action is based on the supersymmetric generalized self-duality
in odd dimensions developed originally by Townsend, Pilch and van
Nieuwenhuizen. Even though such a self-duality had been supposed to be very
difficult to generalize to a supersymmetrically interacting system, we show
that Dirac-Born-Infeld action is actually compatible with supersymmetry and
self-duality in three-dimensions. The interactions can be further generalized
to arbitrary (non)polynomial interactions. As a by-product, we also show that a
third-rank field strength leads to a more natural formulation of self-duality
in 3D. We also show an interesting role played by the third-rank field strength
leading to a supersymmetry breaking, in addition to accommodating a
Chern-Simons form.Comment: 12 pages, no figure