Khaoui was chosen in the squad that competed at the World Cup in Russia four years ago and, although infrequently played for Tunisia since, had been expected to be included given his form in Ligue 1 for his club Clermont.
A total of 10 players survive from the squad that competed at the last World Cup, where Tunisia were beaten by both Belgium and England but did win their last group game against Panama.
Veteran goalkeeper Aymen Mathlouthi (38), captain in Russia, returns to the squad after a three-year absence in a list of four goalkeepers for the tournament.
Tunisia play a warm-up friendly against Iran in Doha on Wednesday, before taking on Denmark, Australia and France in Group D as they look to advance past the first round for the first time in six World Cup finals appearances.
Tunisia Squad
Goalkeepers
Aymen Dahmen (CS Sfaxien)
Bechir Ben Said (US Monastir)
Mouez Hassen (Club Africain)
Aymen Mathlouthi (Etoile Sahel)
Defenders
Ali Abdi (Caen)
Dylan Bronn (Salernitana)
Mohamed Drager (FC Luzern)
Nader Ghandri (Club Africain)
Bilel Ifa (Kuwait SC)
Wajdi Kechrida (Atromitos)
Ali Maaloul (Al Ahly)
Yassine Meriah (Esperance)
Montassar Talbi (Lorient)
Midfielders
Mohamed Ali Ben Romdhane (Esperance)
Ghaylane Chaalali (Esperance)
Aissa Laidouni (Ferencvaros)
Hannibal Mejbri (Birmingham City)
Ferjani Sassi (Al Duhail)
Elyas Skhiri (FC Cologne)
Forwards
Anis Ben Slimane (Brondby)
Seifeddine Jaziri (Zamalek)
Issam Jebali (Odense)
Wahbi Khazri (Montpellier)
Taha Yassine Khenissi (Kuwait SC)
Youssef Msakni (Al Arabi)
Naim Sliti (Al Ittifaq)
