- Dec 1 American Jacqueline Hansen runs female world record marathon 2:43:54.5 in Culver City, California
- Dec 1 South Africa is awarded the Davis Cup tennis title after India refuses to travel to South Africa for the final in protest of the South African government's apartheid policies
- Dec 2 MLB Rules Committee changes long time philosophy to permit the use of cowhide, rather than just horsehide in the manufacture of baseballs
- Dec 5 Birmingham Americans defeat the Florida Blazers 22-21 in the WFL's World Bowl
- Dec 5 NFL's Seattle Seahawks forms
Richards' 1st Test Century
Dec 14 Viv Richards scores 1st Test Cricket ton 192 v India 20 fours 6 sixes
Vilas Wins ATP
Dec 15 Guillermo Vilas of Argentina beats defending champion lie Năstase 7–6, 6–2, 3–6, 3–6, 6–4 to win his first and only season-ending ATP Masters Grand Prix tennis final in Melbourne, Australia
- Dec 19 Dave Kryskow scores Washington Capitals 1st NHL shorthanded goal
Esposito Scores 500
Dec 22 Phil Esposito, Boston, became 6th NHLer to score 500 goals
Steelers Defeat Raiders
Dec 29 AFC Championship, Oakland Coliseum: Pittsburgh Steelers beat Oakland Raiders, 24-13
- Dec 29 NFC Championship, Metropolitan Stadium, Bloomington: Minnesota Vikings beat Los Angeles Rams, 14-10
- Dec 31 41st Sugar Bowl: #8 Nebraska beats #18 Florida, 13-10
Goolagong Retains Title
Dec 31 Australian Open Women's Tennis: Australian Evonne Goolagong Cawley retains her title; beats Martina Navratilova of Czechoslovakia 6-3, 6-2
Johan Cruyff Wins Again
Dec 31 Ballon d'Or: Ajax forward Johan Cruyff wins back-to-back awards, and his 3rd overall, for best European football player ahead of Bayern Munich defender Franz Beckenbauer and Legia Warsaw midfielder Kazimierz Deyna
- Dec 31 New York Yankees sign Cy Young Award winner Jim "Catfish" Hunter for 5 years for a record $3.75 million from the Oakland A's
Baseball Players
Basketball Stars
Boxers
Footballers
NFL Stars
Tennis Champions