O'Donnell overcame Gerard Greene 6–4 to qualify for the International Championship and lost 6–2 to Neil Robertson in the first round.&lt;ref name="2015/16"&gt;&lt;/ref&gt; In the first round of the Welsh Open he knocked out Stephen Maguire, making a 130 break along the way, but was then defeated 4–2 by Matthew Stevens. O'Donnell beat another multiple ranking event winner when he recovered from 3–1 down to Mark Williams to triumph 5–3 and qualify for the China Open. He then ousted Joe Swail 5–2 and Matthew Selt 5–1 to reach the last 16 of a ranking event for the first time, but he was thrashed 5–0 by Mark King.