<p>Deficits in executive functions (EFs) and impulsive decision-making are well-established cognitive mechanisms underlying gambling disorder (GD), though there are some inconsistent findings. This study investigated the relationship between changes in GD symptoms in online sports bettors and specific EFs as well as decision-making processes over time. A subsample of online sports bettors (<i>n</i> = 54, mean age = 33, 96% male) from a larger study underwent an in-person assessment. Initial GD symptom severity was measured online according to DSM-5 criteria and was low to mild in most participants. All other assessments took place an average of 443 days later, during the in-person assessment. We analyzed cross-sectional and longitudinal associations between three facets of EFs (response inhibition, cognitive flexibility, and working memory) and four decision-making facets (delay discounting, probability discounting for gains and losses, and loss aversion) and GD symptom severity and changes over time. Cross-sectional results showed that higher GD symptom severity was associated with poorer working memory and reduced loss aversion. Reduced loss aversion was also associated with greater symptom increase over time. However, these associations were not statistically significant after correction for multiple testing, so they should be interpreted with caution. No other significant relationships were found. These findings provide preliminary evidence that reduced loss aversion is one cognitive factor in disordered gambling among online sports bettors, a population with heterogeneous profiles of EFs and decision-making. Further longitudinal studies are needed to clarify the role of specific cognitive processes in the development and progression of GD to better inform treatment strategies.</p>