<p>Physical inactivity remains a pressing public health challenge among college students. Tai Chi is an accessible low-intensity exercise for campus settings, but research on its motivational drivers remains limited. Most studies use variable-centered approaches and overlook gender-specific motivational patterns for traditional sports. This study identifies latent Tai Chi motivation profiles among college students using Self-Determination Theory, and examines links between profiles, gender and participation behavior. We analyzed data from 1191 undergraduate students recruited from two public universities in South China through convenience sampling, with a balanced gender distribution of 620 males and 571 females. We measured Tai Chi motivation and participation with validated scales, and used latent profile analysis, R3STEP procedure and BCH method to identify subgroups, test gender as a predictor, and compare participation across profiles. We identified four distinct motivational profiles, with the Moderate Autonomous Profile as the dominant subgroup at nearly 65% of the sample. Gender significantly predicted profile membership. Female students had higher odds of belonging to the High Autonomous Profile, while male students were more likely to fall into the High Mixed Motivation Profile. Tai Chi participation showed a significant gradient across all profiles. This study is the first to identify latent motivational profiles of Tai Chi among college students using Self-Determination Theory, extending the cross-cultural applicability of the theory to traditional Chinese sports through a person-centered lens and informing gender-responsive interventions to promote Tai Chi engagement in universities.</p>