This paper uses random assignment in professional golf tournaments to test for peer effects in the workplace. We find no evidence that playing partners' ability affects performance, contrary to recent evidence on peer effects in the workplace from laboratory experiments, grocery scanners, and soft-fruit pickers. In our preferred specification we can rule out peer effects larger than 0.043 strokes for a one stroke increase in playing partners' ability. Our results complement existing studies on workplace peer effects and are useful in explaining how social effects vary across labor markets, across individuals, and with the form of incentives faced.