The World Group was the highest level of Davis Cup competition in 1981.

[1] It was the first edition of the newly formed 16-team World Group and a move to a tiered system including promotion and relegation.

The first-round losers would play in the Davis Cup World Group Relegation Play-offs, with the four losers relegated to their respective Zonal competitions the following year and replaced by the four winners of the current year's Zonal competitions.

The final was held at the Riverfront Coliseum in Cincinnati, Ohio, United States from 11 to 13 December.

The winners of the play-offs advanced to the 1982 Davis Cup World Group, and the losers were relegated to their respective Zonal Regions.