Montgomery plays in the East Kilbride & District Darts League and in the Glasgow Premier League. He is a multiple time Rutherglen / East Kilbride singles champion. As of 2014, Montgomery has represented Scotland at four
WDF World Cups, four
WDF Europe Cups and six BDO Six Nations Cups. He has played in thirty-six matches for Scotland, winning twenty-four of them. Montgomery qualified for the
2006 BDO World Championships along with players like
Brian Woods and eventual champion
Jelle Klaasen of the Netherlands. Montgomery was drawn in the first round with another Dutchman
Vincent van der Voort, losing 3–1 in sets. He followed this, however, by reaching the final of the Scottish Open, beating
Gary Robson and
Michael van Gerwen before losing in the final to
Sweden's
Göran Klemme, runner-up in the 2005 World Masters. He played in the 2007 International Darts League, beating
PDC player
Chris Mason,
Belgium's
Dirk Hespeels and avenged his Lakeside defeat by van der Voort to win Group 4 with a 100% record. He wasn't able to repeat his performances in the Last 32 Group stage, losing all 3 of his games in Group D to
Martin Atkins,
Scott Waites and group winner
Raymond van Barneveld. Montgomery produced a good run in the
Winmau World Masters, reaching the last 16 of the tournament, losing to Atkins. In 2008, Montgomery won the newly created EDO England Open, which was run by the newly formed
English Darts Organisation. He scored wins over
Johnny Nijs,
Ted Hankey, Gary Robson and Edwin Max before beating another Scotsman
Gary Anderson in the final. He then reached the final of the inaugural BDO International Open, an event formerly known as the BDO England Open, losing to Davy Richardson. On 26 July 2008 Montgomery won his second event of the year, winning the British Classic, again beating Anderson in the final. Montgomery regained the British Classic crown in 2010, defeating
Stuart Kellett in the final. Montgomery ended 2008 ranked seventh on the year end WDF World rankings. These performances helped Montgomery earn automatic qualification for the
2009 BDO World Championships as the number 10 seed. He defeated Welshman
Martin Phillips in the first round but lost in round two to eventual champion Ted Hankey. He entered the tournament the following year as the Number 6 seed, but wasted six darts to win his first round match and lost to
Garry Thompson. Montgomery won the 2010 British Classic as well as the 2010
Zuiderduin Masters, his inaugural major title, where he came from 4–0 down in sets to win 5–4 against
Robbie Green, also surviving three match darts. Montgomery finished as the year end number one in
WDF Working Rankings Europe for 2010. At the
2011 BDO World Darts Championship, Montgomery was beaten 3–1 in sets by
Alan Norris. Montgomery reached the semi-finals of the 2011 Winmau World Masters where he was beaten in a deciding leg by
Dean Winstanley. Following his victory at 2010 edition, Montgomery had another decent run reaching the semi-finals of the Zuiderduin Masters in
2011. At the
2012 BDO World Darts Championship, Montgomery reached the second round for only the second time courtesy of a 3–1 win over Fabian Roosenbrand in the first round, but was subsequently defeated 4–1 by eventual runner-up
Tony O'Shea. Montgomery was defeated in the first round of the
2013 BDO World Darts Championship 3–1 by
Paul Jennings, having had four darts to lead 2–1. Montgomery captained Scotland to silver behind England in the overall team competition at the
2013 WDF World Cup, while alongside team-mates
Gary Stone, Craig Baxter and Alan Soutar, Scotland defeated America 9–7 in the men's team final. He repeated this strong form at the 2025 World Seniors Champion of Champions, with wins over Trina Gulliver,
Raymond van Barneveld, before defeating defending champion, Richie Howson 8–5. Ross was due to face either
Neil Duff or
Richie Burnett, after their first round clash in the 2025 World Seniors Matchplay. However, it was announced in August, that the tournament was cancelled, after the WSD collapsed. ==Personal life==