Coaching in the workplace is the process of indirectly helping employees do their jobs more effectively by asking them empowering questions. Coaching is now a billion dollar business, but the science that supports coaching as an effective business practice is lagging behind the claims of success (“It changed my life!”). To rectify this problem, we meta-analyzed 21 peer-reviewed studies (N = 1009). We computed the standardized mean differences (effect size, d) for these interventions, and then calculated the weighted mean effect sizes. Coaching improved employees’ organizational commitment (d = 1.16), job performance (d = 0.86), goal setting skills (d = 0.41), management skills (d = 0.41), well-being (d = 0.40), self-efficacy (d = 0.32), and self-awareness (d = 0.05). These studies indicate that coaching is generally effective and warrants the investment in it that organizations are making.