O'Shea entered the 2010 BDO World Championship as the number one seed. He had a tough first round against World Masters runner up Robbie Green but came through it 3–2. He then saw off Stephen Bunting 4–0 to reach his fourth Quarter Final. He managed a 5–1 victory over Robert Wagner in the Quarter finals and went on to meet Dave Chisnall in the semi-final who had beaten Fitton in the first round, former Masters champion Tony West in the second round, and defending champion Hankey in the quarter-final. O'Shea, despite taking the first two sets, was beaten 6–3 by Chisnall and saw his World Championship dream end for another year. Martin Adams went on to defeat Chisnall in the final.