At the international level, he represents Solomon Islands. He plays primarily as a Defender. His current market value is estimated at 75K €.

His most recent move was a from Adelaide Cobras FC to Solomon Kings FC on 2026-01-01.

Throughout the OFC Pro League 2026, William Komasi featured in 6 matches, averaging 0 tackles, 0 interceptions, and 0 clearances per game, while blocking 0 shots per game.