This study explores the effect of various sources of information on youth athletes' perceived competence across a sports season. Of interest was how relationship variables (e.g., parent, peer and coach) and motivational variables (e.g., task and ego orientation) affected perceived competence at three-time points during a sports season. Two studies were conducted: A metaanalysis was undertaken to determine current understanding of these relationships within published research literature, and a quantitative study of 182 youth athletes (95 male, 87 female), ranging in age from 6 to 17 years, with an average age of 11.82 was conducted, using a planned missing data design. Both the meta-analysis and the quantitative study found task and ego orientation to have a positive relationship with perceived competence. Results from the metaanalysis also suggested that ego orientation may be differentially related to perceived competence as a function of culture (i.e., individualistic vs collectivist). The quantitative study looked at both between and within-person variability across a sports season. Results suggested that while relational and motivational variables were related to perceived competence in expected ways, perceived competence was also sensitive to changes, relative to the average, of both relationship quality and motivational variables, across a sports season. Results of the present thesis can be used to educate both coaches and parents as to the complex role that significant relationships and motivational climate play in understanding perceived competence in youth athletes.