As the starting quarterback for the Saskatchewan Roughriders for 16 seasons, he led the team to its first Grey Cup championship in 1966 and is the franchise's all-time leader in passing yards, attempts, completions, touchdowns, and interceptions.

After his retirement as a player, he served as a head coach and general manager in the CFL; he led his teams to two Grey Cups and currently ranks fourth all-time with 142 regular season wins.

Lancaster was born in the Pittsburgh area industrial town of Fairchance, Pennsylvania and moved to nearby Clairton as a young boy.

His college coach had a friend with the Ottawa Rough Riders in the Canadian Football League (CFL), and Lancaster signed with them.

During his rookie season in 1960, Lancaster shared the quarterbacking duties with another future Hall of Famer, Russ Jackson, and also played defensive back.

In 16 seasons with the Roughriders (1963–1978), he led the team into the playoffs 14 consecutive years and made it to the CFL's Western Football Conference final 12 times.

During that period, Saskatchewan played for the Grey Cup five times (1966, 1967, 1969, 1972, and 1976) and won it once, in 1966, when they defeated Lancaster's former team, the Ottawa Rough Riders, 29–14.

He was the first quarterback in CFL history to reach 50,000 career passing yards, won the Schenley Award as most outstanding player in 1970 and 1976, was an All-Canadian in 1970, 1973, 1975 and 1976 and a Western all-star in 1966, 1968, 1969, 1970, 1973, 1975 and 1976.

[5] In November 2006, the Canadian sports network TSN ranked Lancaster seventh on its list of Top 50 Players of the CFL's modern era.