The preliminary round of the 2021 Africa Cup of Nations qualification tournament decided four teams which advanced to the group stage of the qualification tournament.

The preliminary round consisted of the eight lowest-ranked teams among the 52 entrants: Liberia, Mauritius, Gambia, South Sudan, Chad, São Tomé and Príncipe, Seychelles, and Djibouti.

[1] The eight teams were drawn into four ties and played in home-and-away two-legged format.

The four winners advanced to the group stage to join the 44 teams which entered directly.

Chad won 5–4 on penalties and advanced to qualification Group A.