"His contract is for a period of four years," the FTF said in a press release, confirming reports that had been circulating for several days.
Chaabani won the African Champions League twice and five Tunisian league titles with Esperance Tunis and has also coached in Egypt and then in Morocco, where he won the league title with RS Berkane.
Berkane had already said Chaabani was taking over Tunisia.
The 45-year-old Tunisian is his country's fourth coach this year and eighth since January 2024.
Ahead of the World Cup, Tunisia raised hopes as they qualified without conceding a goal, even though they started the process under Jalel Kadri and ended it under Sami Trabelsi, with Montasser Louhichi coaching two qualifiers as an interim. Faouzi Benzarti and Kais Yaakoubi also came and went quickly during a break for AFCON qualification.
After Tunisia were knocked out of AFCON in the round of 16 in January, Trabelsi was replaced with Sabri Lamouchi.
When the team opened the World Cup by crashing 5-1 to Sweden, the former France star was axed, and French veteran Herve Renard was brought in. He led Tunisia to two more heavy group-stage defeats.
Chaabani was under contract at Berkane until 2027, but the club said it had decided to show "understanding" because of "the particular importance of the role of managing the national team."
The club praised Chaabani's "great professionalism", saying he had helped "write an important chapter in the history of RS Berkane."
