The team plays in green and white colours, with a reversed away strip. London Irish won its first major trophy in 2002, claiming the Powergen Cup (the competition that later became the Anglo-Welsh Cup). Irish also reached the final of the 2009 Guinness Premiership, narrowly losing 10–9 to Leicester Tigers at Twickenham Stadium. In the 2007/08 season the team came close to a place in the Heineken Cup Final losing out to Stade Toulousain 15–21 in a tense semi-final encounter at Twickenham Stadium. The club's mascot is an Irish Wolfhound called Digger.
London Irish play at the Madejski Stadium, in Reading. Madejski is the home of Reading FC and was opened in August 1998. The ground is a 24,161 all-seater capacity stadium, and was the largest used as a regular home ground in the premiership before Wasps moved to the Ricoh Arena in 2014.
With the exception of the annual London Double Header at Twickenham, all London Irish home matches are played at the Madejski. The largest crowd for a London Irish match was for a game against London Wasps on 15 March 2008 during the 2007–08 Guinness Premiership. The crowd of 23,790 was also the highest attendance for a regular season Guinness Premiership match until December 2008.
London Irish also host London Irish Amateur RFC (a separate legal entity) for non-professionals to allow them to improve in Rugby. The team play at the location of London Irish's training ground and offices, Hazelwood in Sunbury. Some players such as Justin Bishop and Kieran Campbell have come through the ranks to play for London Irish.
Digger was joined by his cousin, Duggie, from the 2006/07 season. Much taller and much slower, Duggie has proved popular with younger children attending matchdays although Digger remains the Top Dog. As well as the two mascots, there is also a real Wolfhound, Mr Doyle, who also attends the home games. Before Mr Doyle there was also another Wolfhound, Jumbo, before Jumbo retired.