He did his secondary education at Colégio São Bento, where he learned his first foreign languages (Latin, English, Spanish, French).
He and his brother Augusto de Campos, together with Décio Pignatari, formed the poetic group Noigandres that published the experimental journal of the same name, which would launch the Brazilian movement of poesia concreta (concrete poetry).
Haroldo received his doctorate from the Faculty of Philosophy, Letters and Human Sciences of USP (Universidade de São Paulo), under the guidance of Antonio Candido.
He translated, major names of world literature, such as Goethe (German), Ezra Pound, James Joyce (English), Mayakovsky (Russian), Mallarmé (French), Dante (Italian) and Octavio Paz (Spanish).
On stage, his works have been performed by three actors: Giulia Gam (1989, Cena da Origem, directed by Bia Lessa), Bete Coelho (1997, Graal: Retrato de um Fausto Quando Jovem, by Gerald Thomas) and Luiz Päetow (2015, Puzzle, by Felipe Hirsch).