He was born in Trenque Lauquen, province of Buenos Aires, in 1892. He resided in Italy from 1908 onwards and studied drawing and painting in Milan until 1914. He participated in a Futurist free exhibition held at the Umanitaria, Milan, in 1911.
Back in Argentina, he worked as a teacher from 1925 to 1929. He reassumed his artistic activities in Milan, and had exhibitions in Bardi, Poligono, Casa d'Artisti, Il Milione, and Mascioni galleries, among others. Together with the Italian non-figurative artists, he took part in the exhibition of Brera in 1938, and the exhibition at the Galería Moody of Buenos Aires, in 1936. In 1942 his works were exhibited at the Mascioni gallery together with the works of the non-figurative group of Como. He also participated with the Futurist artists in the Biennial of Venice and in the Quadriennale of Rome.
He returned to Buenos Aires in 1949 where his works were exhibited at Van Riel, La Máscara and Antú galleries. An important exhibition of the collection of Ugo Bernasconi was made in 1951, which included two non-figurative oils by Juan Bay.
He joined the Madí Group in 1952, being part of the group exhibitions held at the Krayd gallery, Buenos Aires, and the Numero Gallery, Florence, both in 1955. He also participated in exhibitions held in Buenos Aires at Galería Bonino in 1956 and Galería Van Riel in 1957. His works were also included in Art Madí International, Groupe Argentin hosted by the Gallery Denise René, Paris, in 1958.
His works integrated the I Muestra Internacional del Museo de Arte Moderno (I International Exhibition of the Museum of Modern Art) of Buenos Aires, in November, 1960. In 1976 he attended Homenaje a la vanguardia argentina de la década del ’40 in (A Tribute to the Argentine Vanguard of the 40s, hosted by Galería Arte Nuevo.
His production is seen in significant European collections, among them, the Museum of the Castello Sforzesco, and the Museum of Modern Art, both in Milan.
The Galerie de La Salle, Saint Paul de Vence, France, hosted a retrospective exhibition of his work in 1978, the year he died.