The present study aims to provide information about the antioxidant capacity and secondary metabolites from different plant parts of two species that are grown in Ecuador:Chionanthus pubescens(the Ecuadorian national tree), andChionanthus virginicus(the fringe tree—endemic to the United States of America and adapted to Ecuador’s physiographical and ecological conditions). These two species have still not been investigated for these characteristics. A comparative estimation of the antioxidant activities between the leaf, fruit, and inflorescence extracts was performed. In the quest for new medicines, the extracts were analyzed for phenolic, anthocyanin, and flavonoid content. A slight difference was observed betweenC. pubescensandC. virginicusflowers, the highest antioxidant activity being found in theC. pubescensleaf (DPPH IC50= 62.8866 mg/mL, ABTS IC50= 55.852 mg/mL, and FRAP IC50= 2.8466 g/mL). Our results showed correlations between antioxidant activity, total phenolic content, and flavonoids. This study confirmed that theC. pubescensleaves and fruits from the Andean region of Ecuador represent a good source of antioxidants, especially due to the presence of a high content of phenolic compounds (homovanillic acid, 3,4 dimethoxyphenylacetic acid, vanillic acid, gallic acid, etc.) as determined by the HPLC-DAD method.