The defender joined the club in August 2012, and has helped the side into the top four so far this season.
The defender has been used fairly regularly by manager Ronald Koeman this season, making 12 appearances in all competitions, scoring one goal.
The Japanese international - who is participating in the Asia Cup for his nation this month, making him unavailable for the Saints - has been in and out of the side. At the start of the campaign he made three consecutive starts before injury struck in September, meaning he didn't make another start until the 2-1 defeat to Manchester United in December.
The 26-year-old is proving to be a useful member of Koeman's squad, even if he may not be the first choice defender for the Saints by playing in both the right-back and central positions when required, especially when the side have decided to adopt a back three where his versatility shines through and takes on even more value.
Yoshida has been with the side ever since the start of their current spell in the Premier League, by joining under Nigel Adkins, and also worked under Mauricio Pochettino.