The 1975 Detroit Lions season was the 46th season in franchise history. It was the first season for the Detroit Lions at the new Pontiac Metropolitan Stadium in Pontiac, a Detroit suburb, which was built specifically for the team. It was also their first ever season outside Detroit since the franchise's move and name change in 1934; its first three seasons were played in Portsmouth, Ohio as the Portsmouth Spartans. For the seventh consecutive season, the Lions finished the season in second place.