The 2005 K League Championship was the ninth competition of the K League Championship, and was held to decide the 23rd champions of the K League. After the regular season was finished, the first stage winners, the second stage winners, and the top two clubs in the overall table qualified for the championship. Each semi-final was played as a single match, and the final consisted of two matches.
Ulsan Hyundai Horang-i won 6âÂÂ3 on aggregate.