Kaja Erzen is a 32-year-old professional football player from SLO. He currently plays for Ternana W, wearing the number 22 shirt. At the international level, he represents Slovenia Women. He plays primarily as a Defender. His preferred foot is Right.

Throughout the Italian Serie A Women 2025-2026, Kaja Erzen featured in 15 matches, averaging 0.3 tackles, 0.1 interceptions, and 0.5 clearances per game, while blocking 0 shots per game.