Group III may refer to:
Chemistry In the periodic table Group III formerly included these: Group 13 elements: boron (B), aluminium (Al), gallium (Ga), indium (In), thallium (Tl). Group 3 elements: scandium (Sc) and yttrium (Y) plus the lanthanide and actinide series elements.
Biology The dsRNA viruses (e.g. Rotavirus) according to the Baltimore classification. Group III introns, a class of introns found in mRNA genes of chloroplasts in euglenoid protists.
Other Group III motor oil base stock as classified by the American Petroleum Institute