This study developed and validated a measure of Locus of Control in university students. Tertiary academic locus of control is the general expectancy that university students have regarding their ability to change their academic outcomes. Students who have an internal academic locus of control expect that their own efforts, skill, or luck will lead to academic success, while those with an external locus of control believe that academic outcomes are a result of luck, destiny, fate, or the behaviors of others. A series of steps were taken to develop the Tertiary Student Locus of Control (TSLOC) scale. These steps included defining the construct, developing a nomological network of the construct, and constructing an item pool of 66 items. Following the creation of the item pool, an item analysis was conducted on the 66-item measure to produce the 30-item TSLOC scale. The draft scale was administered to 100 participants (80 females and 20 males predominantly of Afro-Caribbean heritage from English-speaking Caribbean islands). The TSLOC scale had an internal consistency of 0.96 and had strong concurrent validity and moderate discriminant validity. A principal component analysis indicated that the TSLOC was a multidimensional scale composed of three underlying dimensions. The TSLOC scale was found to be valid and reliable for the current population of Caribbean tertiary students. The limitations and implications are discussed.