The 1975 NASCAR Grand National Winston Cup Series was the 27th season of professional stock car racing in the United States and the 4th season in the modern era of the NASCAR Cup series. The season began on Sunday, January 19 and ended on Sunday, November 12. Richard Petty, driving the #43 Petty Enterprises STP Dodge scored his sixth NASCAR Grand National Series Winston Cup Championship. Bruce Hill was named NASCAR Rookie of the Year. NASCAR introduced a new points system for 1975, a system designed by statistician Bob Latford. For the first time, each race on the NASCAR Winston Cup Grand National schedule carried an equal point value, a system that would be used for 36 seasons, from 1975 to 2010, with modifications in 2004 and 2007 each time by increasing the emphasis for a win in adding five additional points each time for a race winner. The original points system ran for the first 29 seasons, from 1975 to 2003. Richard Petty's championship would also be the last for Chrysler Corporation, and the last for a Dodge driver until Brad Keselowski in 2012.

Season recap

1975 Season races

Round 1: Winston Western 500

Round 2: Daytona 500

Round 3: Richmond 500

Round 4: Carolina 500

Round 5: Southeastern 500

Round 6: Atlanta 500

Round 7: Gwyn Staley 400

The 1975 Gwyn Staley 400 took place on April 6 at North Wilkesboro Speedway.The race was dominated by Richard Petty, who led a total of 311 laps and won by a margin of over three laps.

Round 8: Rebel 500

Round 9: Virginia 500

Round 10: Winston 500

Round 11: Music City 420

Round 12: Mason-Dixon 500

Round 13: World 600

Round 14: Tuborg 400

Round 15: Michigan 400

Round 16: Firecracker 400

Round 17: Nashville 420

The 1975 Nashville 420 took place on July 20 at Nashville Speedway. Cale Yarborough dominated the race after passing Walter Ballard on lap 50, leading the rest of the laps afterwards and winning.

Round 18: Purolator 500

Current rules state a black flag assessed at the end of the race results in a time penalty, primarily for driving standards or track limits. This was assessed on Ricky Rudd at Sonoma in 1991 (inappropriate contact), Chase Briscoe at Indianapolis in 2021 (track limits, then inappropriate contact when under penalty), or Shane van Gisbergen at Austin in a second tier series race in 2024 (exceeded track limits in Maggots-Becketts-Chapel on final lap).

Round 19: Talladega 500

Round 20: Champion Spark Plug 400

Round 21: Southern 500

Round 22: Delaware 500

Round 23: Wilkes 400

Round 24: Old Dominion 500

Round 25: National 500

Round 26: Capital City 500

Round 27: American 500

Round 28: Volunteer 500

Round 29: Dixie 500

Round 30: Los Angeles Times 500

Full Drivers’ Championship

(key) Bold – Pole position awarded by time. Italics – Pole position set by owner's points.

• – Most laps led.