The Asia/Oceania Zone was one of the three regional zones of the 2018 Davis Cup. In the Asia/Oceania Zone there were four different tiers, called groups, in which teams competed against each other to advance to the upper tier. Winners in Group I advanced to the World Group Play-offs, along with losing teams from the World Group first round. Teams who lost their respective ties competed in the relegation play-offs, with winning teams remaining in Group I, whereas teams who lost their play-offs were relegated to the Asia/Oceania Zone Group II in 2019.