"I can't wait to get started. I'm very, very happy," the 27-year-old, who will wear the number 33 shirt, said. "I'm excited to be here at this massive club with lots of history.
"I'm excited to meet my team-mates, excited to get started playing, and I'm very motivated and really up for getting going.
"I think it was the ideal move for me at this stage in my career, a move that was necessary for me to take. As soon as I heard that interest from Liverpool, everything went into action really, really quickly."
The move, completed at Liverpool's AXA Training Centre and subject to a successful work permit application and international clearance, includes an option to buy and joins Araujo up with Andoni Iraola's squad. The Uruguay international, who joined Barcelona from Boston River in 2018 and can play at right-back as well as centre-back, becomes the fourth Uruguayan to represent Liverpool, following Luis Suarez, Sebastian Coates and Darwin Nunez.
Araujo spoke of the influence both compatriots had on his decision, describing childhood memories of watching Suarez's spell at Anfield between 2011 and 2014.
"We loved watching the English Premier League and everyone in Uruguay gets up early in the morning to catch the games," he said. "Of course as a kid I used to watch Luis playing all those fantastic games for Liverpool. We all know what he achieved, the history that he made within this club during his time here. So it's fantastic.
"From minute one, I've been sort of asked about that kind of comparison since I've arrived here. I get on really well with him, we're quite close. Just a few minutes ago I got a good luck message from him saying all the best, you've joined a great club and all the very best for your time here."
Nunez, a close friend since childhood, also passed on his own well wishes, according to Araujo.
"A big thank you for the message from Darwin," he said. "He's a good mate of mine. We've known each other and played together since we were kids, basically. He's always spoken highly of Liverpool, for sure. When you're out with Darwin, people are always shouting his name and things like that. He's told me about how the fans would recognise him and say, 'Nunez, Nunez!'"