In 1985, Tomkins first made the Australian national team as stroke of the senior men's eight for the 1985 World Rowing Championships in Hazewinkel Belgium.
The Australian VIII finished in ninth place.
In 1986, the Australian eight stroked by Steve Evans won a gold medal at the 1986 World Rowing Championships in Nottingham, England with Tomkins rowing in the six seat.
That same crew rowed to victory at the 1986 Commonwealth Games in Edinburgh, and Tomkins won a Commonwealth Games gold medal.
Tomkins also stroked a coxed four to a bronze medal at those same games.

At the World Championships in Copenhagen 1987 Tomkins was in the six seat when the men's VIII finished in fourth place  and at the 1988 Summer Olympics, the Australian eight finished fourth with Tomkins again rowing at six.

In 1990 with his Mercantile clubmates Samuel Patten & Mike McKay and Nick Green from the Melbourne University Boat Club, Tomkins began racing an Australian representative coxless four.
 Their success was immediate.
 They won the 1990 and 1991 World Championships.
After Andrew Cooper replaced Samuel Patten, they followed up with a gold medal at the 1992 Summer Olympics in Barcelona.
The crew's success gained them the nickname Oarsome Foursome and lifted the profile of rowing in Australia.
The crew repeated its gold medal performance at the 1996 Summer Olympics, this time with Drew Ginn replacing Andrew Cooper.

At the 1998 World Championships, the Oarsome Foursome raced and won the men's coxed four world title with Brett Hayman in the stern.
Tomkins, Green and Hayman also took the world title at that same regatta as a coxed pair.
In 1999, the boat would go on to try out, but lose the 1999 Australian selection trials in a coxless four.
 Tomkins and Drew Ginn decided to switch to a coxless pair and won the 1999 World Championship.
This win established Tomkins as the first man to win a gold medal at World Championships in each of the five sweep rowing events.

Tomkins and Ginn had planned to row the pair at the 2000 Summer Olympics in Sydney, but while in Europe preparing for the games, a severe back injury requiring surgery sidelined Ginn.
 On short notice, Tomkins teamed with team alternate Matthew Long, (who had to switch from stroke side to bow side) and they raced a surprising third at the Lucerne World Cup race.
 Tomkins and Long were selected to represent Australia, and at the Olympics, they finished third behind France and the United States, just 1.3 seconds out of first place.

Returning to a coxless pair in 2002, Ginn and Tomkins beat the heavily favoured British crew of Matthew Pinsent and James Cracknell in a world cup race before finishing a close fourth at the 2002 World Championships.
  In 2003, Ginn and Tomkins reversed the prior years result winning the 2003 World Championship, with Pinsent and Cracknell placing fourth.
In 2004, Pinsent and Cracknell moved to the coxless four to better their chances for a medal.
 Ginn and Tomkins would go on to win the coxless pair at the 2004 Summer Olympics, leading at every mark, beating Croatia by 2 seconds, with South Africa claiming the bronze.

Tomkins was selected in the men's eight for the 2007 World Rowing Championships in Munich, placing a disappointing 4th.
 He competed in his sixth Olympic Games at Beijing  following the disqualification of the Russian Federation boat as a result of a doping scandal.
Tomkins was the Australian flag bearer at the Opening Ceremony.
 Tomkins and his crew finished last in the final of the men's eight and 6th overall at the Beijing Games.

He is one of four athletes to compete in rowing at six Olympics, along with Romanian Elisabeta Oleniuc Lipă in 2004, Canadian cox Lesley Thompson, and Estonian Jüri Jaanson.
In 1985, Tomkins first made the Australian national team as stroke of the senior men's eight for the 1985 World Rowing Championships in Hazewinkel Belgium. The Australian VIII finished in ninth place. In 1986, the Australian eight stroked by Steve Evans won a gold medal at the 1986 World Rowing Championships in Nottingham, England with Tomkins rowing in the six seat. That same crew rowed to victory at the 1986 Commonwealth Games in Edinburgh, and Tomkins won a Commonwealth Games gold medal. Tomkins also stroked a coxed four to a bronze medal at those same games.
At the World Championships in Copenhagen 1987 Tomkins was in the six seat when the men's VIII finished in fourth place  and at the 1988 Summer Olympics, the Australian eight finished fourth with Tomkins again rowing at six.
In 1990 with his Mercantile clubmates Samuel Patten & Mike McKay and Nick Green from the Melbourne University Boat Club, Tomkins began racing an Australian representative coxless four.  Their success was immediate.  They won the 1990 and 1991 World Championships. After Andrew Cooper replaced Samuel Patten, they followed up with a gold medal at the 1992 Summer Olympics in Barcelona. The crew's success gained them the nickname Oarsome Foursome and lifted the profile of rowing in Australia. The crew repeated its gold medal performance at the 1996 Summer Olympics, this time with Drew Ginn replacing Andrew Cooper.
At the 1998 World Championships, the Oarsome Foursome raced and won the men's coxed four world title with Brett Hayman in the stern. Tomkins, Green and Hayman also took the world title at that same regatta as a coxed pair. In 1999, the boat would go on to try out, but lose the 1999 Australian selection trials in a coxless four.  Tomkins and Drew Ginn decided to switch to a coxless pair and won the 1999 World Championship. This win established Tomkins as the first man to win a gold medal at World Championships in each of the five sweep rowing events.
Tomkins and Ginn had planned to row the pair at the 2000 Summer Olympics in Sydney, but while in Europe preparing for the games, a severe back injury requiring surgery sidelined Ginn.  On short notice, Tomkins teamed with team alternate Matthew Long, (who had to switch from stroke side to bow side) and they raced a surprising third at the Lucerne World Cup race.  Tomkins and Long were selected to represent Australia, and at the Olympics, they finished third behind France and the United States, just 1.3 seconds out of first place.
Returning to a coxless pair in 2002, Ginn and Tomkins beat the heavily favoured British crew of Matthew Pinsent and James Cracknell in a world cup race before finishing a close fourth at the 2002 World Championships.   In 2003, Ginn and Tomkins reversed the prior years result winning the 2003 World Championship, with Pinsent and Cracknell placing fourth. In 2004, Pinsent and Cracknell moved to the coxless four to better their chances for a medal.  Ginn and Tomkins would go on to win the coxless pair at the 2004 Summer Olympics, leading at every mark, beating Croatia by 2 seconds, with South Africa claiming the bronze.
Tomkins was selected in the men's eight for the 2007 World Rowing Championships in Munich, placing a disappointing 4th.  He competed in his sixth Olympic Games at Beijing  following the disqualification of the Russian Federation boat as a result of a doping scandal. Tomkins was the Australian flag bearer at the Opening Ceremony.  Tomkins and his crew finished last in the final of the men's eight and 6th overall at the Beijing Games.
He is one of four athletes to compete in rowing at six Olympics, along with Romanian Elisabeta Oleniuc Lipă in 2004, Canadian cox Lesley Thompson, and Estonian Jüri Jaanson.
James Tomkins (rower)