The top-flight champions dethroned Bayern Munich last term and accumulated 90 points from 34 games, while Stuttgart qualified for the Champions League, finishing second with 73 points.
Match preview
Given Bayern Munich had won 11 league titles in a row and somehow managed to win the Bundesliga in 2022-23 despite numerous poor performances, many had thought it impossible to topple the Bavarians.
Fewer still had thought that Leverkusen would be the team to end Bayern's period of dominance, especially as prior to Alonso's arrival the club had never won the Bundesliga.
Their unbeaten domestic double was a welcome relief for fans as the successes of 2023-24 ended their branding as "Neverkusen", a mocking title given to them in light of their failure to win major silverware in the late 90s and early 2000s.
To add to this, despite being heavily linked to the top job at Liverpool, Real Madrid and Bayern Munich, Alonso committed his immediate future to the club and will help his side defend their league title against Vincent Kompany's Bayern in 2024-25.
As well as Alonso's commitment to Leverkusen, star players such as Florian Wirtz, Granit Xhaka and Jeremie Frimpong all remain at the club, and this puts them in a good position to defend their Bundesliga crown.
It should be noted that Die Schwarzroten come into the game having only won one of their four pre-season matches, though results in friendly fixtures can often be misleading.
Opponents Stuttgart had a fantastic season themselves, and their points total of 73 was an improvement of 40 on 2022-23's tally.
Perhaps their season was overshadowed by Leverkusen's remarkable triumph, but the fact that the visitors finished above Bayern Munich and qualified for the Champions League for the first time since 2009-10 should not be overlooked.
Stuttgart's achievement last season is made even more impressive when considering they were in Germany's second division in 2019-20 and were bottom of the table in April 2023 when boss Sebastian Hoeness took charge.
Hoeness's side picked up 13 points from their last eight league matches in 2022-23, and even then only survived relegation from the Bundesliga thanks to their 6-1 aggregate win against Hamburg in the relegation playoff tie.
Last term, Die Roten scored 78 goals and conceded 39 times, and this made them the division's third-best offensive and joint second-best defensive team in the Bundesliga.
Stuttgart's pre-season form has been excellent, with the club winning five of their six friendly fixtures, including a 4-0 win last time out against Athletic Bilbao on August 10.
Bayer Leverkusen friendly form:
Stuttgart friendly form:
Team News
Alonso will have a full roster of players to choose from ahead of the Super Cup final, and he will likely name as strong an XI as he possibly can.
Expect regulars Jonathan Tah, Alex Grimaldo and Piero Hincapie to start in defence, while signing Aleix Garcia could come on in the second half.
As for the visitors, they will have to cope without top scorer Serhou Guirassy and defender Hiroki Ito, who left the club to join Borussia Dortmund and Bayern Munich respectively.
Striker and new signing Ermedin Demirovic could feature alongside Deniz Undav, both of whom will hope to replicate Guirassy's offensive output.
Elsewhere, Dan-Axel Zagadou has been out of action since January due to a cruciate ligament injury.
Bayer Leverkusen possible starting lineup:
Hradecky; Tapsoba, Tah, Hincapie; Frimpong, Xhaka, Andrich, Grimaldo; Wirtz, Adli; Boniface
Stuttgart possible starting lineup:
Nubel; Stenzel, Rouault, Chabot, Mittelstadt; Silas, Karazor, Stiller, Fuhrich; Demirovic, Undav
We say: Bayer Leverkusen 3-1 Stuttgart
Although Leverkusen have struggled for results in their pre-season fixtures, they have retained their best players and will have the opportunity to build on the success of last season.