Self-referent performance beliefs can influence people's decision making related to long-term goals. Current measures of such beliefs, however, do not explicitly focus on the long-term aspects of goal achievement. We introduce a new concept, Long-Term Prospects (LTP), which is defined as the self-perception that one can maintain the continuous effort needed to achieve long-term goals. We developed a measure of LTP and demonstrated across three studies (n > 1,900) that college students' LTP predicted their academic performance, as defined by self-reported grade point average (GPA) and official GPA. Moreover, LTP predicted GPA better than commonly used measures of grit, conscientiousness, and academic self-concept. Multiple regression and Bayesian results showed that LTP accounted for unique variance in the prediction of college GPA above and beyond intelligence, prior achievement, and demographics. Tests for moderation effects suggested that students who had low high school achievement or a low need for achievement especially benefited from having strong beliefs about their ability to maintain effort over the long term. These studies suggest that self-referent beliefs about one's ability to maintain the effort needed to achieve long-term goals are important for academic success and that the LTP measure captures individual differences in these beliefs. The implication is that cultivating students' belief that they can maintain long-term effort, especially in low-achieving students, may yield positive outcomes in their academic performance.