The 1970 AFC Championship Game was the inaugural title game of the American Football Conference (AFC). Played on January 3, 1971, the game was hosted by the AFC East champion Baltimore Colts who played the AFC West champion Oakland Raiders at Memorial Stadium in Baltimore, Maryland. Along with the 1970 NFC Championship Game played on the same day, this game constituted the penultimate round of the 1970–71 NFL playoffs which had followed the 1970 regular season of the National Football League.

Baltimore defeated Oakland 27–17 to earn the right to represent the AFC in Super Bowl V.

Following Super Bowl IV, the NFL and rival American Football League completed their planned merger into a single league, which retained the NFL's established name and logo. As per the terms of the merger, three "old guard" NFL teams (the Colts, Cleveland Browns and Pittsburgh Steelers) agreed to join the ten AFL teams to form the American Football Conference. The other thirteen teams that contested the 1969 NFL season formed the National Football Conference.

The merger meant that the Super Bowl, originally established an interleague World Championship Game between the champions of the AFL and NFL, became the championship game of the NFL. From a mathematical perspective, the AFC Championship Game became the successor contest to the AFL Championship Game which had determined the AFL's champions during its ten-year run from 1960 to 1969, as well as its representative in the first four Super Bowls.

Both conferences were aligned into three divisions each and a new playoff format was established for both new conferences. Under the new format, the division champions qualified in addition to the Best Second Placed Team (which was quickly shortened, first informally and then officially, to wild card) to form a four team bracket in each conference. The home teams were determined at this time by an annual rotation between the three divisions, with the provision that wild card teams would neither host a playoff game, nor face their own division champion prior to the title game. The winners of the Divisional Round would contest the conference championship games, with the winner of the divisional-round game involving two division champions hosting the title game.

In addition to being the inaugural AFC title game, this was the first-ever game (regular season or playoffs) between the Colts and Raiders. Prior to this season, the teams had played in different leagues, and they did not meet in the 1970 regular season.

The Colts had appeared in four NFL title games prior to the merger. They won three of those games, with their final such victory being the only previous title game appearance in the Super Bowl era. Baltimore won the AFC East with an 11–2–1 regular season record and shut out the AFC Central champion Cincinnati Bengals 17–0 at Memorial Stadium in the divisional round to advance to the AFC Championship game.

This was the Raiders' fourth consecutive title game appearance, and also their fourth title game overall. Oakland had won the 1967 AFL Championship Game but lost the AFL title games in 1968 and 1969. The Raiders won the AFC West with an 8–4–2 regular season record. Oakland defeated the AFC East runner-up Miami Dolphins 21–14 at Oakland Coliseum in the divisional round to reach the AFC title game.