The Liverpool duo were included in a team that was decided by votes from more than 23,000 professional footballers.
A total of seven representatives from the European champions appeared on the 55-man shortlist, with Alisson and Van Dijk then being selected as the best players in their respective positions during the 2018-19 season.
The XI was revealed during the Best FIFA Football Awards in Milan on Monday evening.
FIFA FIFPro Men's World11: Alisson Becker, Matthijs De Ligt, Sergio Ramos, Virgil van Dijk, Marcelo, Luka Modric, Frenkie De Jong, Kylian Mbappe, Lionel Messi, Eden Hazard, Cristiano Ronaldo.