Fonseca grew up in the West Village of Manhattan, New York City, where his father had his sculpture studio.
[2] He lived for five years in Barcelona, Spain, where he studied under Augusto Torres, whose father had taught Gonzalo Fonseca in Uruguay in the 1940s.
[3] After this he spent some time in Uruguay, moved for several years to Pietrasanta, close to the marble quarries of Carrara in north-western Tuscany, Italy, and then lived and painted in Paris.
He returned to New York and in 1993 had his first solo show at the Charles Cowles Gallery in SoHo, Manhattan, after which the Metropolitan Museum bought two of his paintings.
[4] Fonseca had a one-man exhibition at the Institut Valencià d'Art Modern in Valencia, Spain, in 2003, and at the Corcoran Gallery of Art in Washington, DC, in 2004.