In the Sri Lanka cricket team, Gayan Wijekoon is a left handed batsman and left arm medium bowler. He has also played for teams like Tamil Union Cricket and Athletic Club, Sri Lanka A, Sinhalese Sports Club, Chilaw Marians Cricket Club and Basnahira North.
Gayan Wijekoon debuted in Test cricket from 13th to 16th July 2005 at Colombo against West Indies. He bowled 10 overs in the 1st innings, out of which 1 was maiden, conceded 49 runs and took 2 wickets. He batted at the No. 8 spot and scored 12 runs in 21 balls. In the 2nd innings, he was not offered bowling and he did not get a chance to bat. Sri Lanka won this match by 6 wickets. On 14th September 2007, Wijekoon debuted in Twenty20 Internationals at Johannesburg against Kenya. He was assigned the No. 8 batting position where he scored 1 run in 1 ball. He took 1 wicket in the 3 overs he bowled and gave away 12 runs. Sri Lanka won this match by 172 runs.
Gayan Wijekoon bowled 114 balls, off which 66 runs were scored, in the 2 Test matches he played. He took 2 wickets at a bowling strike rate of 57, economy rate of 3.47 and batting average of 33. He participated in 3 Twenty20 Internationals in which he bowled 66 deliveries and was hit for 101 runs. His economy rate was 9.18, bowling average 50.50, bowling strike rate 33 and he took 2 wickets.