This work analyses the motivational regulation, achievement goals and sport commitment of Spanish Masters swimmers, being the first study of its kind. A total of 211 (106 women and 105 men) Masters swimmers from the Federation of Castilla-La Mancha (Spain) aged between 20 and 74 participated. Each participant completed the Sport Motivation Scale (motivation regulation), the Achievement Goals Questionnaire for Sport (achievement goals) and the Sport Commitment Questionnaire (sport commitment), all validated for the Spanish population. A mixed rANOVA was performed to analyse the results, using sex and age group as covariates, and the different groupings of the sample (weekly training days, weekly training hours and practice of other sports) as between-participants factors. The results showed that the participants presented a predominantly intrinsic–integrated and identified regulation, rather than introjected and external regulation. Mastery goals were more prevalent than performance–approach and performance–avoidance goals. In addition, current sport commitment was high, being greater than future commitment. Pearson’s correlation analysis showed moderate relationships between our variables. We found no influence of either the covariates of sex and age or the grouping variables. These findings serve as the basis for further study of the motivation of Masters swimmers in Spain.