In sport, the Third Division, also called Division 3, Division Three, or Division III, is often the third-highest division of a league, and will often have promotion and relegation with divisions above and below.

• Belgian Third Division, third-highest level in Belgian football
• Cypriot Third Division, third major league of Cyprus
• Danish 3rd Division, third level of the Danish football league system
• Egyptian Second Division B, third level of the Egyptian football league system
• Football League Third Division, third tier of English football from 1920 until 1992
• French Division 3 (disambiguation)
• Galway & District League Third Division, fourth tier of the Galway & District League football
• Hong Kong Third Division League, third level of football of the Hong Kong Football Association
• Liga Indonesia Third Division, lowest level of nationwide football competition in Indonesia
• Interdistrict Division Three, fifth tier of football in the Northern New South Wales Australia
• Iran Football's 3rd Division, fourth-highest division in the Iranian football system
• Kildare Senior Football League Division 3, Kildare Gaelic Athletic Association
• Kolmonen – Finnish League Division 3, fifth level in the league system of Finnish football
• Lebanese Third Division, third division of Lebanese football
• Leinster League Division Three, third division of the Leinster League
• Libyan Third Division, third tier of Libyan football
• Maltese Third Division, lowest league level in Maltese football
• Norwegian Third Division, fourth-highest division of football in Norway
• Terceira Divisão, fourth level of the Portuguese football league system
• Russian Amateur Football League or III Division, fourth tier of the Russian football league system
• Scottish Football League Third Division, fourth-highest division in the Scottish football system
• Sligo Intermediate Football League Division 3 (ex Div. 2), Sligo Gaelic Athletic Association
• Swedish Football Division 3, fifth level in the league system of Swedish football
• Swedish Women's Football Division 3, fourth level in the league system of Swedish women's football
• Victorian State League Division 3, fourth tier football competition in Victoria, Australia
• Welsh Football League Division Three, fourth level of the football league system in south Wales
• York Football League Division Three, fourth level in the York Football League system

• AIB Division Three, rugby union league in Ireland
• NCAA Division III, the third tier of intercollegiate sports in the United States
• FFHG Division 3, ice hockey, France
• IIHF World Championship Division III, lowest level of the International Ice Hockey Federation
• National Conference League Division 3, fourth division in the British Amateur Rugby League
• North Division Three (shinty), fourth tier of the Shinty league system in Scotland
• Portuguese Handball Third Division, fourth handball league in Portugal
• Rugby Football League Championship Third Division, third level of Britain's Rugby Football League
• Scottish National League Division Three, one of Scotland's national rugby union league divisions
• Speedway National League Division Three, third division of motorcycle speedway in the United Kingdom
• WRU Division Three East, a rugby union league in Wales
• WRU Division Three North, a rugby union league in Wales
• WRU Division Three South East, a rugby union league in Wales
• WRU Division Three South West, a rugby union league in Wales
• WRU Division Three West, a rugby union league in Wales

• 3rd Division (disambiguation), for usage of the term in the military
• DIII (disambiguation)