There are purported relationships between fundamental motor skills (FMS), health-related physical fitness, physical activity, and obesity among children. The purpose of this observational, secondary data analysis was to further examine these associations in children from the 2012 National Youth Fitness Survey (NYFS). 121 five-year old children (51% female) from the NYFS database completed the Test of Gross Motor Development, 2nd edition (TGMD-2), muscular fitness measures of plank and modified pull-ups, and weight status based on body mass index (BMI) percentile. Significant positive correlations were identified between TGMD-2 scores and both pull-ups and plank. Linear regression models, controlling for sex, weight status, and Hispanic ethnicity also identified both modified pull-ups completed and plank time as significant predictors of TGMD-2 total raw score. No demographic factors were significant factors in any of the models. This secondary data analysis identified associations between FMS and health-related physical fitness (i.e., muscular fitness), with both modified pull-ups and plank performance, in five-year old children. Results underscored the importance of different facets of health-related physical fitness contributing significantly to FMS performance and the need for more work related to physical fitness in preschool-age children.