He currently plays for OFI Crete, wearing the number 5 shirt. He plays primarily as a Defender. His current market value is estimated at 500K €.

His most recent move was a from Olympiacos Piraeus to OFI Crete on 2025-07-22.

Throughout the Super League Greek 2025-2026, Konstantinos Kostoulas featured in 22 matches, averaging 0.2 tackles, 0.2 interceptions, and 0.9 clearances per game, while blocking 0 shots per game.