Control beliefs are widely acknowledged to play a critical role in self-regulation and well-being, but their impact on decisions to approach or avoid situations that vary in emotional valence remains unclear. We propose that two contradictory, yet equally intuitive, predictions can be made about the impact of control beliefs on emotional situation selection. On the one hand, control beliefs might encourage individuals to initiate proactive emotion regulatory efforts, helping people select positive situations. On the other hand, control beliefs might promote a sense of confidence in one’s ability to manage emotions once they arise, helping people select negative situations. We propose that both effects occur via different mechanisms and suppress one another: control beliefs facilitate (1) positivity engagement by enhancing awareness of opportunities to regulate emotions, and (2) negativity engagement by enhancing confidence in one’s ability to handle negative situations. We found support for this framework in four studies. Consistent with our hypotheses, control beliefs (measured in Studies 1–3 and manipulated in Study 4) exerted two simultaneous and competing effects on emotional situation selection (assessed via self-report measures in Studies 1 and 2 and behaviorally in Studies 3 and 4) via the proposed mechanisms, and evidence of suppression was found. New opportunities for research on control beliefs, emotion regulation, and motivation are discussed.