The purpose of the current research was to gather baseline data on female youth to inform the development of a targeted physical activity (PA) and sports-based intervention, specifically identified as “Gaelic4Girls”. Cross-sectional data on PA levels, psychological correlates of PA, anthropometric characteristics, and the fundamental movement skill (FMS) proficiency of female youth (n = 331; M age 10.92±1.22) were collected. A subsample (n = 37) participated in focus group (FG) interviews exploring perceptions of health/sport, and identifying barriers/motivators to participation. PA levels were assessed using self-report (PA Questionnaire for Older Children) and classified as low, moderate, and high active. One- and two-way ANOVAs (post hoc Tukey honest significant difference [HSD]) were used to analyze the data. The FGs were transcribed verbatim, coded, and thematically analyzed. Findings indicated that the majority of youth (71.8%) were not meeting the minimum daily PA recommendations for health, and that 98.1% did not achieve the FMS proficiency expected for their age. Low, moderately, and highly active participants differ significantly in terms of overall FMS (p = .03), and locomotor control scores (p = .03). FG findings report fun and friendship as key PA motivators, too much competitiveness as barriers, and positive outside encouragement from family/friends/coaches as facilitators encouraging PA engagement. Findings highlight the need for targeting low levels of PA, FMS proficiency in female youth sport interventions, through addressing self-efficacy levels, inclusive of fun, and socially-stimulating PA environments.