On Monday the Three Lions Manager will unveil the full 23-man squad he'll take to Brazil, but it will not include the Chelsea left-back.
The 33-year-old has made 107 appearances for his country, and Hodgson had praise for a player he says was one of the best in the world.
“It has been one of the hardest decisions of my career.”
Roy Hodgson England Manager
"Among many difficult decisions I've had to make for my squad, not selecting Ashley was one of the hardest," Hodgson told TheFA.com.
"He's been an incredible competitor for England, to amass over a century of caps is a truly staggering achievement and he deserves enormous credit for the desire and brilliance which has shone through over the years he has represented his country.
"There are few players who can be considered among the very best in the world, but Ashley in his prime was the best left back without question."
He added: "The most important factor was speaking to Ashley prior to the announcement on Monday, he deserved to hear it directly from me and he took the news with huge grace.
"In two years working with him he has shown nothing but relentless professionalism, and a great hunger to play for England. He is someone I have the utmost respect for and I wished him all the best, he in turn wished the team well this summer.
"Of course I must respect his decision to retire, he has been one of England's finest players, but I want to look to the future.
"It has been one of the hardest decisions of my career."