Supporters were singing the Liverpool anthem “You’ll Never Walk Alone” in the sunshine before the match against the 13-time winners Real at the Stade de France, just north of the city.
A huge sea of red shirts surrounded the Cours de Vincennes area in the south-east area of the city during the day, where a fan zone has been set up.
As many as 50,000 supporters, largely ticketless, began gathering early during the day, bringing traffic in the area to a standstill as roads were closed off.
Footballs were being kicked into the air and banners being flown while flares - prohibited by French authorities – were let off in the fan zone.
The huge crowd then sang the club’s famous anthem before cheering club legend Kenny Dalglish to a stage which had been set up.
Liverpool have won six European Cups – more than any other British team – with the most recent coming under current manager Jurgen Klopp in 2019.
Only around 20,000 supporters each from Liverpool and Real will officially be able to watch the match at the Stade de France.