In what was a lacklustre affair, the match ended goalless, with only 3 shots on target, after 120 minutes of play.
Liam Moore and Jordan Obita missed two spot-kicks for Reading, which allowed Terriers defender Christian Schindler to step and slot home the goal that would secure his club the richest prize in world football.
For their troubles, Huddersfield will receive approximately £170m for gaining promotion to the Premier League.
The Terriers will join England's top flight for the first time since 1972.
HUDDERSFIELD TOWN ARE PROMOTED TO THE PREMIER LEAGUE!
4-3 on penalties https://t.co/wWPihWvkgp#PlayOffFinal#bbceflpic.twitter.com/caXAlIbuEl
— BBC Sport (@BBCSport) May 29, 2017