Ernesto Fonseca Carrillo (born 1930 or 1942), commonly referred to by his alias Don Neto, is a convicted Mexican drug lord and former leader of the Guadalajara Cartel, a defunct criminal group based in Jalisco.
He headed the organization alongside Miguel Ángel Félix Gallardo and Rafael Caro Quintero.
Fonseca Carrillo was involved with drug trafficking since the early 1970s, primarily in Ecuador, and later moved his operations to Mexico.Fonseca is the uncle of former Juarez Cartel leader, Amado Carrillo Fuentes.