The victory, achieved in extra time, secured a 3-2 aggregate qualification for the record six-time winners.
Lamela's crucial header early in extra-time completed an impressive comeback, setting up a final clash against Jose Mourinho's Roma in Budapest.
Dusan Vlahovic, a substitute who had just come on, fired Juventus ahead in the second half, infusing the Italian side with hope.
However, Suso dashed those hopes with a powerful strike from outside the area, equalizing Sevilla and forcing the game into extra time.
In the 95th minute, Lamela showcased his aerial prowess, connecting perfectly with Bryan Gil's cross to score the winner, sending the Ramon Sanchez-Pizjuan stadium into a rapturous celebration.
Sevilla managed to hold on to secure their spot in the final for the first time since 2020.
The defeat is concerning for Juventus, who currently sit second in Serie A but face the possibility of a points deduction that could jeopardize their top-four position.
Winning the Europa League represented an alternative route for Champions League qualification.
Massimiliano Allegri's side, without the injured Paul Pogba, displayed a significant improvement compared to the first leg but ultimately succumbed to the resilient hosts.