1998 Calder Cup playoffs

The 1998 Calder Cup playoffs of the American Hockey League began on April 14, 1998. The sixteen teams that qualified, eight from each conference, played best-of-five series for division semifinals and best-of-seven series for division finals and conference finals. The conference champions played a best-of-seven series for the Calder Cup. The Calder Cup Final ended on June 10, 1998, with the Philadelphia Phantoms defeating the Saint John Flames four games to two to win the first Calder Cup in team history. Philadelphia's Mike Maneluk won the Jack A. Butterfield Trophy as the AHL playoff MVP.

The Philadelphia Phantoms set an AHL playoff record by winning 9 road games in one playoff year.

Playoff seeds
After the 1997–98 AHL regular season, 16 teams qualified for the playoffs. The top four teams from each division qualified for the playoffs. However, due to the uneven number of teams in the each conference, it was possible for the fifth-placed team in the five team divisions to crossover to the playoffs for the four team divisions. This could only happen if the fifth-placed team in a five team division earned more points than the fourth-placed team in the four team division in the same conference. In this case, the fifth-placed team from the five team division would play in place of the fourth-placed team from the four team division in that part of the playoff bracket. The Philadelphia Phantoms were the Western Conference regular season champions as well as the Macgregor Kilpatrick Trophy winners with the best overall regular season record. The Springfield Falcons were the Eastern Conference regular season champions.

Atlantic Division

 * 1) Saint John Flames – 99 points
 * 2) Fredericton Canadiens – 81 points
 * 3) Portland Pirates – 80 points
 * 4) St. John's Maple Leafs – 73 points

New England Division

 * 1) Springfield Falcons – Eastern Conference regular season champions, 99 points
 * 2) Hartford Wolf Pack – 99 points
 * 3) Beast of New Haven – 85 points
 * 4) Worcester IceCats – 83 points

Empire Division

 * 1) Albany River Rats – 103 points
 * 2) Hamilton Bulldogs – 94 points
 * 3) Syracuse Crunch – 83 points
 * 4) Adirondack Red Wings – 74 points
 * 5) Rochester Americans – 72 points (Played in the Mid-Atlantic Division bracket by virtue of earning more points than the fourth-placed team in that division)

Mid-Atlantic Division

 * 1) Philadelphia Phantoms – Western Conference regular season champions; Macgregor Kilpatrick Trophy winners, 106 points
 * 2) Hershey Bears – 85 points
 * 3) Kentucky Thoroughblades – 70 points

Bracket
In each round the team that earned more points during the regular season receives home ice advantage, meaning they receive the "extra" game on home-ice if the series reaches the maximum number of games. There is no set series format due to arena scheduling conflicts and travel considerations.

Division Semifinals

 * Note 1: All times are in Eastern Time (UTC−4).
 * Note 2: Game times in italics signify games to be played only if necessary.
 * Note 3: Home team is listed first.