Gil Díaz is the son of Francisco Gil Arias, a fisherman, and Ana María Díaz Perches.
He is married to Margarita White and has four children: two males and two females.
In the public sector Gil Díaz has served as Undersecretary of Finance (1988–1994) and Vice-Governor of the Mexican central bank (1994–1997). In the private sector he worked as CEO of Avantel, a Mexican telephone and internet service provider (1997 - November 2000).[4]