The deal is believed to have cost the Italian side around €5 million, and it represents their first foray into the transfer market under new sporting director Monchi, who believes that his international experience will prove invaluable.
The 79 cap Mexico international has signed a four-year contract that will run until the summer of 2021 and he leaves Holland having won the Eredivisie title twice, once in 2008/9 with AZ Alkmaar and again in 2015/16 with PSV.
Perhaps better known to English fans as the man who broke Luke Shaw's leg in the Champions League, the former Espanyol man is equally adept at centre-back or left-back, though he prefers the former.
A club statement expressed Roma's delight at sealing a deal for a player that Monchi has been chasing "for some time", not that he will be joining up with his new team-mates anytime soon though, as he is currently away on international duty with Mexico ahead of the Confederations Cup.