2018 Davis Cup Americas Zone Group III

The Americas Zone was the unique zone within Group 3 of the regional Davis Cup competition in 2018. The zone's competition was held in round robin format in Escazú, Costa Rica, from 28 May to 2 June 2018. The two winning nations won promotion to Group II, Americas Zone, for 2019.

Draw

Date: 28 May–2 June
Location: Costa Rica Country 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.

Seeding

Pot	Nation	Rank¹	Seed
1		81	1
1		84	2
2		94	3
2		95	4
3		99	5
3		104	6
4		110	7
4		113	8
4		130	9

¹Davis Cup Rankings as of 9 April 2018

Round Robin

Pool B

''Standings are determined by: 1. number of wins; 2. number of matches; 3. in two-team ties, head-to-head records; 4. in three-team ties, percentage of sets won, then percentage of games won, then Davis Cup rankings.''

Playoffs

' and ' were promoted to Group II in 2019.