My motto is to grow as an institution, as a club and in the basic foundations, the intention is that we all be better.
Hierro will oversee the development of the senior squad and infrastructure around the first-team and academy set-up.
He succeeds Ricardo Peláez, who was dismissed earlier in October following the club's exit in the first round of the LigaMX playoffs which extends their wait for a first trophy since 2017.
An iconic former centre-back for Real Madrid and Spain, Hierro won three UEFA Champions League titles in 14 years with Los Blancos and amassed 89 caps for his country during the same period.
He then took over as Spain's national team Sporting Director from 2007 to 2011, during which time they won UEFA Euro 2008 and the 2010 FIFA World Cup.
He has since been Sporting Director at Malaga CF, Real Madrid's Assistant Manager and the Manager of Real Oviedo before returning to the Spain set-up as Sporting Director and then Caretaker Manager from 2017 to 2018.
Hierro said: "We have to be realistic, we have a plan that we have to follow, but we will not give up any trophy that comes along the way. We will try to do the best possible job to fight for the league and every game we have.
"My motto is to grow as an institution, as a club and in the basic foundations, the intention is that we all be better."
Chivas are one of the teams benefitting from a league-wide deal for Liga MX on TransferRoom.
Direct access to decision-makers at more than 650 clubs worldwide means they can open up a network of potential buyers for their talents, just like Club Necaxa did when they moved Jesus Alcántar to Sporting CP on the platform, the first time they've moved a player to Europe.