Juric, who previously managed Roma and Torino, takes over from the recently dismissed Russell Martin.
The south coast team is nine points adrift of safety as they prepare for their upcoming match against Fulham on Sunday.
Martin’s departure followed a disappointing 5-0 defeat at home to Tottenham last weekend.
The club noted that Juric is known for his ability to enable teams to exceed expectations.
“I’m very pleased,” said the 49-year-old. “I think it’s a really big challenge but I’m very optimistic because I saw a team that can do better.
“It’s important to immediately be connected with the fans. I want an aggressive team and I think that fans of Southampton will like that.”