Organizations increasingly expect employees to demonstrate proactive behaviors. We examined person–organization fit (P–O fit) and person–job fit (P–J fit) as moderators of the relationship between proactive personality and intrinsic career success (job and career satisfaction). We hypothesized that proactive personality would be related to intrinsic career success only to the extent that individuals had high fit with organizations and jobs. In Study 1, using a sample of 295 teachers and 139 of their peers working in 15 elementary and high schools in Turkey, we found that proactive personality was positively related to job satisfaction only for individuals with high P–O fit. Furthermore, proactive personality was positively related to career satisfaction only for individuals with high P–O fit and for individuals with high P–J fit. We replicated the findings for P–O fit as a moderator of personality with respect to job and career satisfaction in Study 2, using a sample of 203 university professors in the United States. We found no support in either sample for P–J fit as a moderator of proactive personality with respect to job satisfaction. In Study 2, we found that research productivity was related to proactive personality differentially for high and low P–J fit tenure-track faculty members.