The 2004 Stanley Cup Finals was a best-of-seven playoff series that determined the National Hockey League (NHL) champion for the 2003–04 season. As a culmination of the 2004 Stanley Cup playoffs, the Eastern Conference champion Tampa Bay Lightning defeated the Western Conference champion Calgary Flames in seven games and were awarded the Stanley Cup. It was Tampa's first-ever appearance in the final. For Calgary, it was the team's third appearance, and first since their championship season of 1989. Lightning owner William Davidson would soon become the first owner in sports history to win two championships in one year as eight days later, the other team that Davidson owned (the Detroit Pistons of the NBA) won the NBA title in five games over the Los Angeles Lakers.

Tampa Bay defeated the New York Islanders 4-1, the Montreal Canadiens 4-0 and the Philadelphia Flyers 4-3 to advance to the Finals.

Calgary beat the Western Conference's top three seeded teams, the Vancouver Canucks 4-3, the Detroit Red Wings 4-2 and the San Jose Sharks 4-2, in that order. This brought a Canadian team to the Finals for the first time in 10 years; Vancouver lost to the New York Rangers in the 1994 Stanley Cup Finals.