Both players received all 100 first-place votes in balloting conducted by a panel of broadcasters and sportswriters. James is a first-team choice for a record 12th time, while MVP favourite Harden was a unanimous selection for the second straight season.
Also earning first-team honors were New Orleans Pelicans big man Anthony Davis (96 first-team votes), Portland Trail Blazers guard Damian Lillard (71) and Golden State Warriors forward Kevin Durant (63).
James, Harden and Davis are the three finalists for NBA MVP, which will be announced at the 2018 NBA Awards on June 25 on TNT.
The All-NBA Second Team consists of Milwaukee Bucks forward Giannis Antetokounmpo, Oklahoma City Thunder guard Russell Westbrook, Philadelphia 76ers center Joel Embiid, San Antonio Spurs forward LaMarcus Aldridge and Toronto Raptors guard DeMar DeRozan.
Named to the All-NBA Third Team were Golden State Warriors guard Stephen Curry, Indiana Pacers guard Victor Oladipo, the Minnesota Timberwolves duo of Karl-Anthony Towns and Jimmy Butler and Oklahoma City forward Paul George.
James was tied with Kobe Bryant and Karl Malone with 11 first-team selections before averaging 27.5 points and recording a career-best 18 triple-doubles in his latest stellar campaign. Harden led the NBA with a 30.4 scoring average and recorded the first 60-point triple-double in league history.
Davis finished second in scoring (28.1) and fifth in rebounding (11.1), Lillard averaged 26.9 points while energizing Portland to the third-best record (49-33) in the Western Conference, and Durant averaged 26.4 points in his latest strong season.
Antetokounmpo averaged 26.9 points per game, while Westbrook became the first player to average a triple-double in two straight seasons with marks of 25.4 points, 10.3 assists and 10.1 rebounds.
Embiid averaged 22.9 points and 11.0 rebounds while leading Philadelphia's rise, Aldridge averaged 23.1 points for a San Antonio team missing Kawhi Leonard for most of the season, and DeRozan (23.0) guided Toronto to a franchise-best 59 victories.
Curry averaged 26.4 points, and Oladipo (23.1) blossomed with Indiana after being acquired in the deal for George, who averaged 21.9 points for the Thunder. Towns led the NBA with 68 double-doubles while teammate Butler averaged 22.2 points.
Among the notable omissions are Houston point guard Chris Paul, Utah center Rudy Gobert and Boston guard Kyrie Irving.
