Following is a thorough and detailed list of all teams ever to have participated in the European competitions organized by UEFA (I disregard the so called Super Cup, which has a quite different competition format). The arrangement of these teams is not done on an alphabetical basis, since I prefer to group them by countries (although each one, this time, has a traditional A to Z order and, in some cases like Germany, Russia, Yugoslavia, and the newborn Soviet and Balkan republics, I include all the political territories a team played for). From the corresponding link of each country you can access to the list of its participating teams, which includes the following data for every club: 1) official team's name in its original language (or a transcription in Roman characters), together with changes of name during its history in Eurocups, including mergers with other clubs; 2) city/-ies where it plays regularly; 3) links to the club's official (OP) or unofficial (UP) pages; 4) participations in Champions League (C1); 5) participations in the late Cup Winners' Cup (C2); 6) participations in Europa League (C3); 7) participations in the late Intertoto Cup (IC).
Mergers and changes of name considered, up to 2017-18 season (included) as many as 1,132 teams have participated in European competitions. On the other hand, I include links to 955 Websites of these teams (855 Official Pages and 100 Unofficial Pages), in which as many as 42 languages are used. In the transcription of names I've used standardized linguistic norms, which apply uniformly to all the teams of the same country, so it's possible you notice some differences in the case of some clubs' names. My ultimate goal is to offer a single, unified terminology which doesn't depend on the spelling of a particular target language.
To access the index of participating countries in Eurocups, click here or follow the corresponding link in the side menu.
The names of teams are written in their original spelling (or a standard transcription into Latin characters, in the case of other alphabets). This is the reason why some clubs may slightly difer in form with respect to other unstandardized information sources.
Sometimes it may be the case that I include an official page of the team together with one or several unofficial pages of it, but this is only when the latter add more information, statistics, or data about the club. Whenever a teams has only unofficial pages, I include as many of them as possible (in case they're informative enough). I do not expressly include pages run by ultra groups or other associations that propagate violent contents or subjects other than football in itself.