He subsequently worked as a Senior Crown Counsel for the government of Saint Vincent and the Grenadines, before being appointed to diplomatic postings "in various capacities in Cuba, Venezuela, Ethiopia, South Korea, Libya and throughout the CARICOM region".

[3] In November 2007, Gonsalves became St. Vincent and the Grenadines' Permanent Representative to the United Nations, replacing Ambassador Margaret Hughes-Ferrari.

[4][5] In September 2013, Gonsalves was appointed as a senator in the House of Assembly of St. Vincent and the Grenadines, and renounced his U.S. citizenship prior to taking up the position.

On 14 December 2015, he was sworn in as Minister of Economic Planning, Sustainable Development, Industry, Trade, Information and Labour.

In a surprise cabinet reshuffle which took effect on 10 November 2017, Gonsalves took on the responsibility of the finance ministry - a portfolio his father had held since his Unity Labour Party administration came to government in 2001[7] - becoming Minister of Finance, Economic Planning and Sustainable Development.