Aston Villa
Villa return to the continent's elite competition for the first time in 41 years but have pedigree having won the European Cup in 1982.
As recently as 2018/19, they were languishing in the second tier, yet Villa have been transformed since Unai Emery's appointment as manager under two years ago.
The Spaniard's tactical nous, allied to some savvy recruitment, has propelled Villa up the Premier League table and saw them beat the likes of Chelsea, Manchester United and Tottenham to finish fourth last season.
Villa Park will host some mouthwatering European nights as Bayern Munich visit in a repeat of the final 42 years ago, while Juventus make the trip to Birmingham before a Battle of Britain against Celtic.
Success or failure will depend largely on Argentina's Emi Martinez performing heroics in goal and England striker Ollie Watkins' ability to make a mark in his first taste of Champions League football.
Stuttgart
Stuttgart are not really newcomers, but they return to the Champions League for the first time since 2010.
After taking over with Stuttgart sitting last in the league late in the 2022/23 season, coach Sebastian Hoeness took the club through a relegation play-off to keep the five-time German champions in the top flight.
Stuttgart then surprised everyone last season, finishing second, 40 points better off than the previous season and above Bayern.
The impressive campaign led to a summer exodus, with prolific striker Serhou Guirassy, defenders Waldemar Anton and Hiroki Ito all leaving for Bundesliga rivals.
The Porsche-backed club invested during the close season, making Germany forward Deniz Undav's loan from Brighton permanent, while signing striker Ermedin Demirovic – the two most expensive deals in club history.
The coach will need to do a similarly impressive job with his new-look side if Stuttgart are to navigate a tough draw, including games against Real Madrid, Juventus and Paris Saint-Germain.
Girona
Catalan minnows Girona thrilled Spain last season in only their fourth top-flight campaign, running eventual champions Real Madrid close for many months.
A third-place finish secured their first taste of European football but Girona's side now looks very different.
Savinho, Aleix Garcia and Artem Dovbyk all departed, leaving coach Michel Sanchez with the job of moulding several new recruits, including Arnaut Danjuma, to the club's swashbuckling attacking gameplan.
Girona, backed by the City Football Group, have been thrown in at the deep end with a visit to PSG first.
They will welcome Liverpool and Arsenal to their 14,500-capacity Montilivi stadium, which the club upgraded to make eligible for Champions League matches. Attendances in Europe will be smaller still to comply with UEFA regulations prohibiting temporary seating.
Bologna
Bologna head into their first-ever match in the modern Champions League in an uncertain state after a poor start this season under new coach Vincenzo Italiano.
Without last season's departed stars Joshua Zirkzee and Riccardo Calafiori, Bologna have undoubtedly been weakened after also losing coach Thiago Motta to Juventus.
They have yet to win in Serie A, picking up three points from four matches.
Bologna played and lost one tie in the old European Cup in 1964, the same year as the last of their seven Italian league titles, and the coming Champions League campaign is new ground for a club whose last major honour was the Italian Cup in 1974.
Brest
Brest will be experiencing European football for the first time after the Brittany club shocked France last season by finishing third in Ligue 1.
With France now getting an extra Champions League place, Brest have benefited and were handed a mouthwatering draw with ties against Real Madrid, Barcelona and Bayer Leverkusen.
Coach Eric Roy has worked miracles since taking over a team in relegation trouble in January 2023, but making inroads in the Champions League may prove too much.
Brest have lost key players, with centre-back Lilian Brassier joining Marseille and left-back Bradley Locko sidelined with a long-term injury.
Furthermore, the Pirates are not able to play games at their own Stade Francis-Le Ble, which does not meet UEFA standards. Instead, they have to decamp over 100 kilometres to Guingamp for home matches.