Introduction: Boredom proneness is linked to poor self-regulation, leading to poor decision making and/or increased risk taking. These links have not yet been investigated in the domain of sports and exercise. However, poor decisions or excessive risk behavior would be highly detrimental to sporting performance and, in some cases, even cause physical harm. Here, we address this gap by assessing if boredom proneness is linked to general risk taking, sport-specific risk taking, and to regrets about sports-specific decision errors with respect to acting too risky or too passively. Methods: N = 936 athletes (27.6 ± 9.0 years, 89.6% men): n = 330 Climbers (31.8 ± 10.7 years, 82.4% men), n = 83 Snowboarders (29.9 ± 8.3 years, 79.5% men), and n = 523 Esports athletes (24.6 ± 6.3 years, 95.8% men) completed the Short Boredom Proneness Scale (SBPS), along with measures for objective risk taking (Balloon Analogue Risk Task; BART), subjective risk taking (general willingness to take risks), as well as assessments for sport-specific risk taking and regrets for sports-specific decision errors (taking too many risks, failing to act at all). In the two extreme sports samples (i.e., climbers and snowboarders), we additionally assessed self-selected outcome certainty in a hypothetical sports-specific scenario where an error would result in physical harm. Results: A series of multiple regression analyses revealed that boredom proneness was unrelated to objective and subjective general risk taking, but a significant predictor of sport-specific risk taking and higher risk taking in the sports scenario (climbers and snowboarders only). Most importantly, boredom proneness predicted regrets for taking too many risks and being too passive. Exploratory post-hoc analyses further indicated that boredom proneness in extreme sports athletes was lower than in esports athletes. Higher boredom proneness was significantly related to lower skill levels across all kinds of sport. Discussion: Across three athlete samples, boredom proneness was unrelated to general risk taking but significantly related to poorer decision making, as indicated by regrets about acting too risky and too passively, as well as demanding a significantly lower safety threshold to make a risky sports-specific choice. While at odds with the often-reported link between boredom proneness and risk taking, these results are consistent with the conceptualization of boredom proneness as a maladaptive self-regulatory disposition that leads to noisy decision making in sports. In addition, we provide preliminary evidence that boredom proneness covaries with self-selection into specific types of sports and might also stand in the way of skill acquisition in sports.