Louzada was born in Rio de Janeiro on April 12, 1912. He began working on the Radio Panamericana radio drama, under the direction of Oduvaldo Viana in 1944. Louzada also filmed two Brazilian movies in 1944, Gente Honesta and É Proibido Sonhar.
Louzada did not begin working in television until 1971. His telenovela credits included Estúpido Cupido (Stupid Cupid), Locomotivas and Vamp. He also appeared in a number of miniseries, including Engraçadinha, O Primo Basílio and O Tempo e o Vento.
In 2003, Louzada was cast in the popular Brazilian telenovela, Mulheres Apaixonadas. He portrayed the elderly character, Leopoldo Duarte, who was married to Flora de Souza Duarte, played by fellow Brazilian actress Carmen Silva. The elderly couple in Mulheres Apaixonadas were often mistreated by their granddaughter, Dóris de Souza Duarte, who was portrayed by actress Regiane Alves.  Louzada's role on Mulheres Apaixonadas earned him a good deal of fame throughout the country.
Oswaldo Louzada's last role in television was in the program, Sob Nova Direção. Louzada, who was a smoker, suffered from several chronic health problems during his final years, including hypertension, lung cancer and heart problems. He died at the Hospital Copa D'Or in Rio de Janeiro of multiple organ dysfunction syndrome on February 22, 2008, at the age of 95. He had been hospitalized for treatment since February 6, 2008. He was buried at the São João Batista Cemetery in Rio de Janeiro.
Actress Carmen Silva, who played Louzada's television wife on the Mulheres Apaixonadas telenovela, also died of multiple organ dysfunction syndrome, the same disorder which afflicted Louzada, two months later on April 21, 2008.
- 2003 Zorra Total
- 2003 Mulheres Apaixonadas .... Leopoldo de Sousa Duarte
- 2002 O Quinto dos Infernos .... Alencastro
- 2000 Uga-Uga .... Moretti
- 1995 Cara e Coroa .... priest (special guest)
- 1995 Engraçadinha... Seus Amores e Seus Pecados
- 1991 Vamp .... priest Eusébio
- 1990 Desejo .... Erico Coelho
- 1989 Pacto de Sangue .... General Tóti
- 1988 O Primo Basílio .... Cunha Rosado
- 1986 Hipertensão .... priest Vicente
- 1985 O Tempo e o Vento .... Florêncio (the old one)
- 1982 Final Feliz .... Olegário
- 1981 Brilhante .... Leonel
- 1979 Cabocla .... Felício
- 1978 Pecado Rasgado .... Bilu
- 1977 Locomotivas .... Chico Rico
- 1976 Estúpido Cupido .... Guimarães
- 1975 Escalada .... Galbino
- 1971 Bandeira 2 .... Lupa Papa-Defunto
- 1955 Leonora of the Seven Seas
- "Ator Oswaldo Louzada morre aos 95 anos no Rio". Folha. 2008-02-22. Retrieved 2008-05-09.
- "Carmen Silva, a Flora de "Mulheres Apaixonadas", morre no RS". Folha. 2008-04-21. Retrieved 2008-05-09.
-  (Portuguese)