  We construct a supergravity solution describing a charged rotating black ring
with S^2xS^1 horizon in a five dimensional asymptotically flat spacetime. In
the neutral limit the solution is the rotating black ring recently found by
Emparan and Reall. We determine the exact value of the lower bound on J^2/M^3,
where J is the angular momentum and M the mass; the black ring saturating this
bound has maximum entropy for the given mass. The charged black ring is
characterized by mass M, angular momentum J, and electric charge Q, and it also
carries local fundamental string charge. The electric charge distributed
uniformly along the ring helps support the ring against its gravitational
self-attraction, so that J^2/M^3 can be made arbitrarily small while Q/M
remains finite. The charged black ring has an extremal limit in which the
horizon coincides with the singularity.
