The avocado (Persea americana), an edible fruit, is one of the main agricultural products in many tropical regions. Avocado fruit is rich in fat, and commercialized for fresh consumption and industrially processed leaving seed as a major residue. Avocado seed from the industry is worthy of attention for certain industrial applications and feasibility. Transforming avocado seed lipids into ecologically friendly or sustainable materials suitable for the cosmetic industry is promising from the perspective of green and environmental protection. The oil contents and fatty acid compositions of the seeds of 16 avocado accessions collected from southern China were investigated, revealing significant differences among most of the accessions. Seventeen fatty acids were identified and quantified by gas chromatography-mass spectrometry in the seeds of all 16 avocado accessions. Linoleic (40.14%), palmitic (23.54%), and oleic acids (16.23%) were the major fatty acids in the seeds, and the total contents of unsaturated fatty acids in the seeds were all higher than those of saturated fatty acids. The biochemical properties of the avocado seed oils relevant to their application in industrial practice were examined [e.g., the acid (3.74 mg KOH/g oil), iodine (124.09 g I2/100 g oil), peroxide (49.83 meq H2O2), and saponification (167.98 mg KOH/g oil) values]. Furthermore, the bar soap containing avocado seed oil was made, and its physicochemical properties (pH and foamability) were evaluated.