He was born Julio José Iglesias-Preysler (before a later name change) in Madrid, Spain, the son of Spanish singer Julio Iglesias and Filipina socialite and "Hola!" magazine Journalist Isabel Preysler. He is the younger brother of Chabeli Iglesias and the older brother of Enrique Iglesias. His parents divorced in 1979; Iglesias Jr. and his siblings moved to Miami in the United States, to live with their father.

In October 1999, he legally changed his name from Julio José Iglesias to Julio Iglesias Jr.

Iglesias Jr. second album, Tercera Dimension, was released in 2003 on the Warner Music Group and featured Spanish pop rock songs with the singles "Los Demas" and "Dejame Volar". Both albums received public interest from the Hispanic media in the United States but attained minority success.

Iglesias Jr. was the winner of the CMT reality Television show Gone Country, in which artists from other genres of music lived together in a house in Nashville and competed to win a country music contract. His single "The Way I Want You" was released to country radio on March 10, 2008 and was produced by Gone Country host John Rich. Iglesias Jr. also appeared on the ABC TV show the superstars. He was partnered by a female soccer player, Brandi Chastain. They finished in fourth place in the competition.

In May 2011 Iglesias Jr. became engaged with Belgian topmodel Charisse Verhaert (born 1982) after 8 years of dating; the wedding took place on 3 November 2012 in Spain.

In 2014, he joined the band Latin Lovers with Nuno Resende and Damien Sargue.

In 2015, he performed a concert (complete show) for the first time with his father Julio Iglesias in a tour in Romania, on 22 May at Sala Polivalentă in Cluj-Napoca and 2 July at Sala Palatului in the capital Bucharest.