A total of 32 players were named for a warm-up match against Catalunya in Barcelona on January 2 followed by a training camp in Portugal. It will be cut to 23 by January 9, the Nigerian football federation said on Saturday.
Odemwingie's exclusion continues a fractious relationship he has had with the Nigeria national team over the last 18 months and opens the door for Shola Ameobi, the former England under-21 international who won his first cap for the Super Eagles in November.
Millwall's Shittu returns for the first time since being dropped last year.
Nigeria will compete against defending champions Zambia, Burkina Faso and Ethiopia in Group C at the Nations Cup finals in South Africa which start on January 19.
Only five players remain from Nigeria's squad at their last major tournament appearance at the 2010 World Cup finals, also in South Africa.
Goalkeepers: Chigozie Agbim (Enugu Rangers), Daniel Akpeyi (Heartland FC), Austin Ejide (Hapoel Beer Sheva), Vincent Enyeama (Maccabi Tel Aviv)
Defenders: Efe Ambrose (Celtic), Elderson Echiejile (Sporting Braga), Azubuike Egwuekwe (Warri Wolves), Benjamin Francis (Heartland FC), Solomon Kwambe, Godfrey Oboabona (both Sunshine Stars), Kenneth Omeruo (ADO Den Haag), Juwon Oshaniwa (Ashdod), Danny Shittu (Millwall), Joseph Yobo (Fenerbahce)
Midfielders: Reuben Gabriel (Kano Pillars), Rabiu Ibrahim (Celtic), Nosa Igiebor (Real Betis), Raheem Lawal (Adana Demirspor), John Obi Mikel, Victor Moses (both Chelsea), Obiora Nwankwo (Padova), Fegor Ogude (Valerenga), Ogenyi Onazi (Lazio)
Forwards: Shola Ameobi (Newcastle United), Bright Dike (Portland Timbers), Emmanuel Emenike (Spartak Moscow), Brown Ideye (Dynamo Kiev), Uche Kalu (Caykur Rizespor), Sunday Mba (Enugu Rangers), Ahmed Musa (CSKA Moscow), Ikechukwu Uche (Villarreal), Ejike Uzoenyi (Enugu Rangers). (Reporting by Mark Gleeson in Durban; Editing by Tom Pilcher)