The 2005 Kelly Cup Playoffs of the ECHL began on April 12, 2005. 16 teams qualified for the playoffs. In the American Conference, the top eight teams qualified for the playoffs. In the National Conference, the top four teams from each division qualified for the playoffs.
The top eight teams in the conference qualified for the 2005 Kelly Cup playoffs, with the division champions seeded 1 and 2 and the remaining six teams seeded 3 through 8 based on points. The Conference quarterfinals featured a best-of-5 series with the higher seeds (1, 2, 3 and 4) versus the lower seeds (8, 7, 6 and 5). The Conference semifinals featured a best-of-5 series as well as a reseeding with the highest remaining seeds hosting the lowest remaining seeds. The Conference finals featured a best-of-seven series with the winner crowned the American Conference champion and granted a berth in the Kelly Cup Finals.
The top four teams in each of the North and West divisions qualified for the 2005 Kelly Cup playoffs. Each divisions' champion would be seeded first in the best-of-5 Division Semifinals hosting the fourth seed from their division, while the second seeds would play the third seeds. The winners of each Division semifinal would move on to the best-of-5 division finals. The winners of the two division finals play in a best-of-seven conference final. The winner of the conference final was crowned the National Conference champions and granted a berth in the Kelly Cup Finals