Osvaldo Máximo Vieira (1938 – 31 March 1974) was a pioneer of the Bissau-Guinean independence movement and a key military commander during the War of Independence. He was the cousin of Nino Vieira, who would later serve two separate terms as president.^[1]

Vieira was one of many early recruits from the so-called "revolutionary petty bourgeoisie", a group which Amílcar Cabral entrusted with instigating the war of independence.^[2] His father worked at the Sociedade Comercial Ultramarina, while his grandfather had worked in the postal service, owned land, and was considered a "small intellectual".^[3]

Before his revolutionary career, Vieira worked as a pharmacy assistant to Sofia Pomba Guerra, a white Portuguese feminist who was active in the burgeoning independence movements of Guinea-Bissau and Mozambique. In 1961 he, along with nine other young PAIGC fighters, trained at the Army Command College of the Chinese People's Liberation Army in Nanjing, China.^[1]

The Osvaldo Vieira International Airport in Bissau is named in his honour.