In June 2014, Koeman was announced as the replacement for Southampton manager Mauricio Pochettino, signing a three-year deal with the club.
His brother Erwin was appointed assistant manager.

In his first six Premier League games in charge of the club, Koeman managed four wins, a draw and a defeat, propelling Southampton to second place in the league standings and resulting in Koeman being named Premier League Manager of the Month for September.
In January 2015, Southampton won all three of their matches, including a first win at Manchester United since 1988, and Koeman was again named Manager of the Month.
He led Southampton to a seventh-place finish at the end of the season.

Koeman won his third Premier League Manager of the Month for January 2016, on the way to Southampton's highest ever Premier League finish, sixth place, highest ever Premier League points total, 63, and qualification for the group stage of the UEFA Europa League.
In June 2014, Koeman was announced as the replacement for Southampton manager Mauricio Pochettino, signing a three-year deal with the club. His brother Erwin was appointed assistant manager.
In his first six Premier League games in charge of the club, Koeman managed four wins, a draw and a defeat, propelling Southampton to second place in the league standings and resulting in Koeman being named Premier League Manager of the Month for September. In January 2015, Southampton won all three of their matches, including a first win at Manchester United since 1988, and Koeman was again named Manager of the Month. He led Southampton to a seventh-place finish at the end of the season.
Koeman won his third Premier League Manager of the Month for January 2016, on the way to Southampton's highest ever Premier League finish, sixth place, highest ever Premier League points total, 63, and qualification for the group stage of the UEFA Europa League.
Ronald Koeman