We study the generalization of S-duality to non-commutative gauge theories.
For rank one theories, we obtain the leading terms of the dual theory by
Legendre transforming the Lagrangian of the non-commutative theory expressed in
terms of a commutative gauge field. The dual description is weakly coupled when
the original theory is strongly coupled if we appropriately scale the
non-commutativity parameter. However, the dual theory appears to be
non-commutative in space-time when the original theory is non-commutative in
space. This suggests that locality in time for non-commutative theories is an
artifact of perturbation theory.Comment: 7 pages, harvmac; a typo fixe