Seed of Annona cinerea grown in Nigeria was investigated for its secondary metabolites and antioxidant potential using Gas Chromatography-Mass Spectrometry (GC-MS), 2,2ʹ- dyphenyl-1-picrylhydrazyl (DPPH) and 2,6-ditert-butyl-4-[(3,5-ditert-butyl-4-λ1- oxidanylphenyl)methylidene] cyclohexa-2,5-dien-1-one (Galvinoxyl), respectively. The antibacterial activity of the seed extract was evaluated on eleven (11) pathogenic bacteria using agar well diffusion method at different concentrations of the extract. Twenty-seven (27) therapeutically active secondary metabolites were identified in the seed extract using GC-MS and the principal constituents identified were 3-O-methyl-d-glucose (52.14%), β-sitosterol (11.79%), desulphosinigrin (6.16%) and α-tocopherol (5.84%). The extract also displayed high DPPH and galvinoxyl radical scavenging activity with IC50 values of 5.0 and 100 μgml-1. The zones of inhibition ranged from 10-30 mm against all tested bacteria. The antibacterial index (AI) ranged between 0.5-25. This study demonstrated that the seed of A. cinerea could be a potential source of natural antioxidants and antimicrobial agents.