2015 Davis Cup World Group

The World Group was the highest level of Davis Cup competition in 2015. The first-round losers went into the Davis Cup World Group play-offs, and the winners progressed to the quarterfinals and World Group spot for 2016.

Seeds
• # (quarterfinals)

• # (first round)

• # (first round)

• # (quarterfinals)

• # (semifinals)

• # (first round)

• # (first round)

• # (quarterfinals)

Great Britain vs. United States

 * The Isner-Ward match was the longest match involving a United States player since the introduction of the tiebreaker in 1989.
 * Great Britain's victory over the United States was their first win over this country at home since 1935.

Czech Republic vs. Australia

 * This was Australia's first World Group win since 2006.

Argentina vs. Brazil

 * The Mayer-Souza match set the record for the longest Davis Cup singles rubber, lasting for 6 hours and 42 minutes, eclipsing the previous record by 20 minutes which was from the McEnroe-Wilander match in 1982. It is the second longest tour match in history, behind the Isner-Mahut match from Wimbledon 2010.

Belgium vs. Switzerland

 * Belgium won a World Group tie for the first time since 2007.

Great Britain vs. France

 * Great Britain won a quarterfinal match for the first time since 1981.
 * It is the first time since 1998 that siblings have combined to win three points in a world group tie. The Black brothers Byron and Wayne did so for Zimbabwe against Australia.

Australia vs. Kazakhstan

 * It was the first time in 76 years that Australia had come back from 2–0 down to win.
 * It was the first time that all four nominated players had played in a singles live rubber tie for Australia.
 * Australia made it into the semifinals for the first time since 2006.
 * Despite having played Davis Cup for 17 years it was the first time that Hewitt had played in the deciding rubber.

Belgium vs. Canada

 * Belgium advanced to the semifinals for the first time since 1999.

Great Britain vs. Australia

 * Great Britain reach their first final since 1978.

Belgium vs. Argentina

 * Belgium reach their first final since 1904 and equal their best Davis Cup performance.

Belgium vs. Great Britain

 * Great Britain win their 10th Davis Cup and their first since 1936.
 * Andy Murray becomes the third player to finish with an 8–0 record in the singles after John McEnroe and Mats Wilander.
 * Andy Murray becomes the fourth player to finish with an 11–0 record in the singles and doubles.