We characterize mildly mixing group actions of a noncompact, locally compact, second countable group $G$ using orbit equivalence. We show an amenable action $\Phi$ of $G$ is mildly mixing if and only if $G$ is amenable and for any nonsingular ergodic $G$-action $\Psi$, the product $G$-action $\Phi\times\Psi$ is orbit equivalent to $\Psi$. We extend the result to the case of finite measure preserving noninvertible endomorphisms, i.e., when $G=\N$, and show that the theorem cannot be extended to include nonsingular mildly mixing endomorphisms.