The World Group was the highest level of Davis Cup competition in 1981. 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 original 16 teams to compete were chosen through the previous year's results, with teams that reached the 1980 Zonal semifinals chosen to compete in the inaugural bracket. 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.
