The 20-year-old, who has eight Under-21 appearances to his name, skippered the side that thrashed Scotland Under-21s 6-0 when senior Three Lions boss Roy Hodgson was in caretaker charge.
Now, Southgate, appointed full-time successor to Stuart Peace last month, has confirmed that Wisdom will continue to wear the armband, starting with the European Championships qualifying match against Moldova on Wednesday.
"It's a great honour to captain any England side at any level so I'm pleased to retain the captaincy and hopefully we can go on and do well," Wisdom told reporters.
"We've got two games coming up so it's a chance to impress everyone and hopefully me and the lads can put a good performance on and show the fans what we're really capable of."
Wisdom, who has made 21 first-team appearances for Liverpool, was poised to move on loan to Wigan Athletic on transfer deadline day before the Reds learned of the potential severity of Glen Johnson's injury.