The 38-year-old world number four has competed at Adelaide twice before, winning both times in 2007 and 2023.
He will be back in the city for the ATP-WTA tournament from January 12-17 ahead of the opening Grand Slam of the year at Melbourne Park which begins on January 18.
Djokovic won his last major in 2023 and has cut down on tour appearances since, but still lifted titles this year in Geneva and Athens.
Other Adelaide entrants include Jack Draper, Joao Fonseca, Tommy Paul and Stefanos Tsitsipas.
Defending Australian Open champion Madison Keys spearheads the women’s field alongside fellow top 10 players Jessica Pegula, Mirra Andreeva and Ekaterina Alexandrova.
“The 2026 edition of the Adelaide International will showcase the tournament’s continued growth and prestige on the global tennis calendar as it attracts world-class calibre from both the WTA and ATP tours,” said tournament director Alicia Molik.