The 2018 Davis Cup was the 107th edition of the Davis Cup, a tournament between national teams in men's tennis. It was sponsored by BNP Paribas. In 2018, new rules were introduced for the Group I and II zonal events, with ties now being played as best-of-three sets over the course of two days. Croatia won their second Davis Cup on indoor clay in the final match held at 25 November with a 3–1 win over France.
Date: 14–16 September 2018 The eight losing teams in the World Group first round ties and eight winners of the Zonal Group I final round ties will compete in the World Group Play-offs for seeded spots in the 2019 Qualifying Round. Seedings are based on Davis Cup rankings as of 9 April 2018. Seeded teams
Date: 28 May–2 June Location: Costa RicaCountry Club, Escazú, Costa Rica Format: Round-robin basis. The winner of Pool A will play-off against the runner-up of Pool B and the winner of Pool B will play-off against the runner-up of Pool A to determine which two nations will advance to Americas Zone Group II in 2019. ;Participating teams ;Pool A
;Pool B
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Play-offs
' and ' promoted to Group II in 2019.
Asia/Oceania Zone
Group I
Group II
Group III
Date: 2–7 April Location: Mỹ Đình Sports Complex, Hanoi, Vietnam Format: Round-robin basis. One pool of 4 teams and one pool of 5 teams. The winner of Pool A will play-off against the runner-up of Pool B and the winner of Pool B will play-off against the runner-up of Pool A to determine which two nations will be promoted to Asia/Oceania Zone Group II in 2019. ;Participating teams ;Pool A
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;Pool B
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Play-offs
' and ' promoted to Group II in 2019.
' and ' relegated to Group IV in 2019.
Group IV
Date: 29 January–3 February Location: Sultan Qaboos Sports Complex, Muscat, Oman Format: Round-robin basis. Two pools of six teams. The winner of Pool A will play-off against the runner-up in Pool B and the winner of Pool B will play-off against the runner-up in Pool A to determine which two nations will be promoted to Asia/Oceania Zone Group III in 2019. ;Participating teams ;Pool A
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;Pool B
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Play-offs
' and ' were promoted to Group III in 2019.
Europe/Africa Zone
Group I
Group II
Group III Europe
Date: 3–7 April Location 1: Tennis Club Lokomotiv, Plovdiv, Bulgaria Location 2: Ulcinj Bellevue, Ulcinj, Montenegro Format: Round-robin basis. Two pools of four teams at each venue. The winners of each pool play-off against each other to determine which nation will be promoted to Europe/Africa Zone Group II in 2019. Two promoted - one from each venue. ;Participating teams ;Pool A
Date: 18–23 June Location: Nairobi Club Ground, Nairobi, Kenya Format: Round-robin basis. One pool of four teams and one pool of five teams. The winners of each pool play-off against each other to determine which two nations are promoted to Europe/Africa Zone Group II in 2019. ;Participating teams ;Pool A
