We present a solution to the minimum time control problem for a classical harmonic oscillator to reach a target energy E[subscript T] from a given initial state (q[subscript i], p[subscript i]) by controlling its frequency [omega], [omega][subscript min] less than or equal to [omega] less than or equal to [omega][subscript max]. A brief synopsis of optimal control theory is included and the solution for the harmonic oscillator problem is used to illustrate the theory. (Contains 6 footnotes and 6 figures.)