The Brazilian will arrive at Anfield on July 1 as one of the most highly-rated young midfielders in Europe, but how exactly has he carved out that reputation during his time in France?
To find out, Liverpoolfc.com spoke to ESPN's Paris-based French football correspondent Jonathan Johnson, who provided the lowdown on a player he expects to prove a big hit in the Premier League.
Get the inside track on what to expect from Fabinho with our Q&A below...
How did Fabinho end up at Monaco?
Fabinho initially arrived on loan at Monaco back in 2013 after a spell with Real Madrid, which was mostly spent with their Castilla team. He remained on loan for his second season and it was only in 2015 that Monaco completed his purchase from Rio Ave. So, to say that he was unheralded when he arrived would be an understatement. However, if he arrived through the back door, he has definitely left through the front.
How did he fare in his first season in France? Did he impress straight away?
Fabinho was a regular in the starting XI from the beginning and played in 21 matches in Ligue 1 alone in 2013-14. However, it was not until Leonardo Jardim arrived in 2014 that he really became a key figure. The Portuguese's tactical innovation to move the Brazilian from right-back to defensive midfield proved a masterstroke.
Did he pretty much hold onto that new position straight away?
It was not immediate. It took Jardim time to get to know his players but once he was more familiar with them, he recognised Fabinho's potential value in midfield and moved him there. His permanent signing coincided with Monaco selling Geoffrey Kondogbia to Inter Milan that summer.
How important was he to the title-winning team of 2016-17?
Extremely important. There were a few key figures in that success and Fabinho was one of the main ones. He started 33 out of 38 possible Ligue 1 matches and featured in 37 of them, so was pretty much an ever-present, scoring nine goals (seven penalties) and providing one assist. His personality made him one of the leaders of the team too.
Was this summer always the right time for Fabinho to move on?
In an ideal world, Monaco would have kept hold of him. However, Fabinho and the club agreed that he could leave last summer until it became obvious that he wanted to join PSG. With Kylian Mbappe already leaving for Paris, Monaco refused to sanction Fabinho's move there as well, which is why he was not allowed to move until this summer. Had it not been PSG pushing hardest to sign him, he probably would have left last year.
Monaco vice-president Vadim Vasilyev was effusive in his praise of Fabinho's character upon his departure - is that something that shone through during his time in France?
Absolutely. Fabinho was one of Monaco's strongest leadership figures and his experience will not be easy for them to replace. He also showed his professionalism in not forcing through the move to PSG that he wanted last summer and staying with Monaco at the detriment of his World Cup chances.
Just how suited is he to Premier League football?
Very. Fabinho has been ready to move on since winning the Ligue 1 title and a change of scene will do him good. I do not see too many problems for him changing from Le Championnat to the Premier League. Coming from France, where there is greater emphasis on tactics, I expect Fabinho to be at a superior level to most Premier League players in that respect. Adapting to life in England might prove a challenge, but compatriot Roberto Firmino will likely be a big help there.
And finally, what can Liverpool fans expect from Fabinho?
Fabinho is combative and physical but he also possesses great technique. He is imposing in the air, comfortable in possession, sees long and short passes early, is not afraid of tackling and stays very composed. Having also played right-back, Fabinho is a versatile figure and should blend well with the likes of Naby Keita.
You can follow Jonathan Johnson on Twitter @Jon_LeGossip, or read more from ESPN by clicking here.