Despite the importance of dispersal in increasing fitness and population persistence, there is a lack of understanding how dispersal proximately affects mate choice (i.e. group formation) and ultimately affects fitness (i.e. breeding success). In this study we investigated long-term patterns of dispersal by African wild dogs in an enclosed population for 90 pack years and modeled how these affected dispersal age, pack formation and breeding success. Dispersal patterns were biased although this was sex-specific across explanatory variables. Females dispersed at higher annual probabilities, at younger ages, and in smaller groups than males. Natal dispersal (i.e. primary) occurred at a younger age for females than males, while female non-natal dispersal (i.e. secondary) occurred at older ages than for males, indicative of mate competition as a mechanism for dispersal in wild dogs. We found evidence suggesting that costs of early dispersal might be offset by emigration in larger groups. Contrary to predictions, younger individuals dispersed in smaller groups during their primary event but in larger groups during their secondary event. Optimal pack formation was not related to timing of dispersal, rather, pack formation was significantly dependent on larger dispersal groups and emigration in the mating and resource abundant seasons. More males, younger individuals, larger packs, larger dispersal groups, and emigration during mating and resource abundant periods resulted in increased fitness. Our results confirm that mate competition (especially among females), inbreeding avoidance and resource competition are important drivers of dispersal in this population of wild dogs.