Liverpool secured their main target of the summer after a months-long pursuit of the speedy 23-year-old France international who is coming off winning back-to-back Champions League titles with PSG, but mainly as an impact substitute, backing up Desire Doue.
Now Barcola will expect to be a key part of an expensively assembled Liverpool attack that also includes striker Alexander Isak and Florian Wirtz, who were signed last summer for Stg 125m and Stg 116m, respectively.
Barcola is primarily a left winger so isn't a like-for-like replacement for Liverpool great Mohamed Salah, who played on the right for nine years before leaving for Trabzonspor to end a trophy-laden spell at Anfield.
"It took a long time," Barcola said, "but I'm really happy today to be able to play for Liverpool and all I want is to be on the pitch and be able to play.
"I hope to achieve very big things. First of all, winning the Premier League – it's one of my biggest dreams in my life.
"It is to do that and to stay in this team in the long term – that's why I signed a long contract – and I hope I can do it."
The deal will involve Liverpool paying $A200m for Barcola and up to an additional $A32m in potential add-ons. Barcola joined PSG for 45m euros ($A73m) from Lyon in 2023.
The fee is a record for a player leaving the French league.
Barcola, a fast and direct winger, joins a team that has made to a sluggish start to the Premier League, with Liverpool needing late goals to salvage draws against Newcastle and Nottingham Forest in the opening two rounds.
Cody Gakpo and summer signing Víctor Muñoz have played on the left wing so far this season. Gakpo has has been a target for Manchester City and Barcola's arrival may enable his exit.
Barcola tops list of costliest Premier League transfers this summer
English clubs have spent big this summer — but this is the biggest deal of the lot topping Morgan Rogers, (Aston Villa to Chelsea for $A218m), Elliot Anderson (Nottingham Forest to Manchester City, $A216m) and Sandro Tonali, (Newcastle to Tottenham, $A186m).