People on the autism spectrum may have difficulty inferring others' emotions (cognitive empathy), but may share another's emotions (affective empathy) and exhibit heightened personal distress. The present study examined independent autistic trait dimensions (social difficulties and restricted/repetitive behaviours) and the roles alexithymia and trait anxiety have in explaining this profile of empathy. Results from the general population (n = 301) revealed that pronounced social difficulties and not restricted/repetitive behaviours related to reduced cognitive and affective empathy, and heightened personal distress. However, both dimensions, through alexithymia and anxiety, indirectly influenced empathy. Surprisingly, while the dimensions indirectly improved affective empathy, pronounced social difficulties directly reduced affective empathy. This study motivates a nuanced model of empathy by including autistic trait dimensions, anxiety, and alexithymia.