Ashworth has been at the Premier League club for eight years and has extensive experience in youth development and the coaching of elite players.
The 41-year-old will not work specifically with the England senior or under-21 setups but will play a key role in the development of the country's elite talent alongside former international Trevor Brooking.
Ashworth will remain in his role at West Brom for the remainder of the current season before joining up with the FA at St George's Park in the summer.
"I am really pleased and indeed honoured to have been offered the opportunity to join The FA," he told the FA's official website.
"Working within the national set-up has always been a life-long ambition. To do so at a time when the future of the game in this country has never looked brighter, through the completion of St. George’s Park and the Youth Development proposals, is an exciting challenge which I look forward to taking on."
Gareth Southgate stepped down as the FA's head of elite development in July.