Alex Gregory began in 2001 with the rowing, in the early years of his career he rowed in Skull - boats. In 2004 he occupied at the U23 World Regatta eleventh place in the quadruple sculls, he was in the double sculls in 2005 and 2006, he finished fourth in the one ninth. 2007 Gregory joined with the British quadruple sculls at the World Championships in Munich and missed with a 15th place qualifying for the Olympics of 2008.
After moving to the Sweep Rowing Alex Gregory won the 2009 in four without the two World Cup regattas in Banyoles and Lucerne, in Munich, the boat reached the third place. In the occupation of Alex Partridge, Richard Egington, Alex Gregory and Matt Langridge the boat also won the title at the World Championships in Poznan. Rowed in 2010, the British foursome in the same occupation and won with Bled and Lucerne again two World Cup regattas, as last year the boat in Munich had become a third party; at the World Championships in New Zealand, the boat was surprisingly only to fourth place. 2011 joined the boat in the cast Langridge, Egington, Tom James and Gregory and won the World Cup regatta in Munich and Lucerne as well as the World Cup final in Bled.
For the Olympic season, the British foursome in 2012 was re- occupied, Alex Gregory, Peter Reed, Tom James and Andrew Triggs Hodge won in the World Cup regattas in Belgrade and Lucerne, at the World Cup final in Munich, the boat took second place behind the Australian foursome. At the Olympic Games in London, the British boat won ahead of the Australians.
From 2013 he sat in the British eighth. The World Rowing Championships in Chungju, South Korea, she won gold and thus defeated Germany the eighth. This had always taken from 2009 to 2011 the world title in 2012 and was also Olympic champion.