Javier Echevarría was born in Madrid on June 14, 1932, the youngest of eight children. He studied at the Marist Brothers' school in Chamberí and began his law degree in Madrid, later completing it at the Lateran University in Rome. He joined the Roman High School of the Holy Cross in 1950 and worked closely with St. Josemaría, starting when he was appointed its secretary in 1953. He held this position until the death of the founder of Opus Dei in June 1975. On August 7, 1955, he was ordained a priest. He accompanied St. Josemaría on his travels throughout Europe and the Americas to promote the apostolic work of Opus Dei.
In 1975, he was appointed University Secretary of Opus Dei. He worked alongside Msgr. Álvaro del Portillo, the first successor of St. Josemaría, until his death in 1994. With the approval of Opus Dei as a personal Prelature, Msgr. Echevarría was appointed Vicar General. The elective congress selected him as Prelate of Opus Dei, an appointment confirmed by Pope John Paul II on April 20, 1994.
He promoted the expansion of Opus Dei across all five continents. Specifically, he initiated apostolic work on a stable basis in fifteen countries: Lithuania (1994), Slovakia, Lebanon, Panama, and Uganda (1996), Kazakhstan (1997), South Africa (1998), Slovenia and Croatia (2003), Latvia (2004), Russia (2007), Indonesia (2008), Romania and Korea (2009), and Sri Lanka (2011). He made numerous pastoral trips to these and other countries to support the faithful of Opus Dei in their apostolic work.
He died in Rome on December 12, 2016.