In 1970 Cummins, at age 11, was spotted by Middlesbrough Chief Scout Ray Grant playing for Ferryhill Grammar School. Some of Grant's other discoveries were Brian Clough, Mark Proctor and Tony Mowbray. Grant told Boro's Assistant Manager Harold Shepherdson that Cummins had the keenest football brain he had encountered in a boy and was the most naturally talented player he had seen since Hughie Gallacher. Shepherdson signed Cummins on Associate Schoolboy Forms for Middlesbrough at age 14, staving off competition from Chelsea, Arsenal and Aston Villa to name a few clubs wanting his signature. Grant died in February 2006.
Cummins began his career with Middlesbrough in 1975 as an apprentice professional and was coached at youth level by former Scotland and Celtic great Bobby Murdoch. He was voted Boro's Young Player of the Year in 1976. Manager Jack Charlton gave him his debut in the old First Division (now called The Premiership) against Ipswich Town at Ayresome Park on November 27, 1976 at the age of only 17 and Cummins went on to become a firm crowd favorite. He played for Boro in a friendly match against Scottish club Hearts a few weeks earlier and scored in a 3-0 win. Cummins signed professional forms with the club on his 18th birthday. He gained renown as a diminutive, skilful striker/midfielder. While still only a teenager Jack Charlton suggested that Cummins would one day be the first player to be sold for one million pounds. However, that was not to be the case for in 1979 Trevor Francis became the first when Nottingham Forest bought him from Birmingham City. In 1977 Cummins had the honor of playing with 1966 World Cup Winner Sir Bobby Charlton in John Hickton's Testimonial Match against Sunderland at Ayresome Park. In the summer of 1977 he played in the North American Soccer League (NASL) at the age of 18 for the Minnesota Kicks against the likes of Pelé, Franz Beckenbauer, Giorgio Chinaglia and his idol George Best, winning the Western Division Championship. In November of '77 Cummins scored his first league goal in Boro's 1-0 win against Aston Villa at Villa Park. By age 19 he established himself in Boro's first team and played in their F.A. Cup run of 1978 that ended with a quarter final defeat by Leyton Orient. In January of that year Boro beat Newcastle United 4-2 at St. James Park and Cummins scored Boro's fourth goal prompting match commentator Kenneth Wolstenholme to say another of his famous one liners. Immediately after the goal Wolstenholme said "That gives him (Cummins) ten out of ten and one for neatness". Cummins played against Scotland in Willie Maddren's Testimonial Match prior to their departure for the 1978 World Cup in Argentina. Former Boro colleague Graeme Souness also played. In February 1979 he was a member of the England U21 Squad versus Wales U21 along with Bryan Robson, Glenn Hoddle, Kenny Sansom and Terry Butcher coached by Dave Sexton and Terry Venables. He also used to write a weekly column for Scoop, a soccer magazine, as did Kenny Dalglish, Glenn Hoddle and Peter Barnes.
Cummins joined Sunderland in November 1979 at the age of 20, for £300,000, the Club's most expensive signing in their 100 year history, scoring on his debut in the 3-1 win over Notts. County at Roker Park. He also won the Daily Express National Five-a-side Championship at Wembley Arena that same month. Cummins would also score vital goals for Sunderland in their promotion season of 1979/80. On February 9, 1980 he scored four goals and had 1 assist in the 5-0 win against Burnley at Roker Park. On April 5 he scored the only goal that beat Newcastle United in the local derby at Roker Park. That record stood for twenty-eight years until Sunderland beat Newcastle United again on home soil on October 25, 2008 when Sunderland won 2-1. He also scored in the 2-0 win against West Ham United to clinch promotion in front of 47,000 fans at Roker Park on May 12. The following season, he would score the goal which ensured Sunderland's First Division survival away to Liverpool at Anfield in the last game of the season. He was named Sunderland Player of the Year for 1981 and also the North-East of England Outfield Player of the Year for 1981. He was also the only Sunderland player to play in all 46 League and Cup games that season. In the summer of 1981 he returned to the NASL and played for the Seattle Sounders alongside Bruce Rioch and Alan Hudson, winning the Trans-Atlantic Challenge Cup against the New York Cosmos, Glasgow Celtic and Southampton. He also played for the Sounders against the Washington Diplomats featuring Dutch legend Johan Cruyff.
In 1983, after his Sunderland contract had expired, Cummins joined Crystal Palace instead of Newcastle United and Kevin Keegan, a move he deeply regrets, returning to Sunderland a year later. He had played with Keegan in John Craggs's Testimonial Match in 1982 and enjoyed Keegan's style of play. His second spell at Roker Park was short-lived. He was a member of the Sunderland Squad who got to the 1985 League Cup Final at Wembley Stadium but couldn't play because he was cup-tied. In all he made 165 appearances for Sunderland. He left the club following relegation in 1985 for the USA at the age of 26 and joined the Minnesota Strikers on a three year contract in the Major Indoor Soccer League (MISL). The Strikers reached the 1986 MISL Championship only to lose 4 games to 3 (best of seven) to the San Diego Sockers. However they were crowned MISL Eastern Division Champions in 1988 and on April 8 Cummins scored a hat-trick in the Strikers 4-2 victory against the Chicago Sting and he was carried shoulder high from the playing field by his team-mates at the end of the game. The club folded at the end of the season and so Cummins joined the Kansas City Comets for the 1988/89 season. He played in all of the Comets games that season along with team-mate Greg Ion. An entertaining and skilful player, Cummins' career spanned 14 years, 10 years in the English Football League where he made 251 appearances in both League and Cup Competitions scoring 50 goals, 2 seasons in the NASL and 4 years in the MISL, USA. He retired as a professional player in 1990 and has a UEFA 'B' coaching certificate.
- "Player of the Day: Stan Cummins", safc.com, 21 August 2013. Retrieved 11 November 2013