It depends on what the object is. For a point mass at the end of a massless string you might use 1/2 m v^2. For a more complicated object that can't be viewed as a point mass you'll want to look at the moment of inertia and rotational kinetic energy. Investigate: "Physical Pendulum".
Just to add: for a point mass, the kinetic energy depends on the speed (##|\vec{v}|^2##) rather than the (vector) velocity, so the direction of travel (e.g. circular motion) doesn't matter.