Brian Howard Clough (/klʌf/ KLUF; 21 March 1935 – 20 September 2004) was an English football player and manager, primarily known for his successes as a manager with Derby County and Nottingham Forest. He is one of four managers to have won the English league with two different clubs. He is widely regarded as one of the greatest managers of all time. Charismatic, outspoken and often controversial, his achievements with Derby and Forest, two clubs with little prior history of success, are rated among the greatest in football history. His teams were also noted for playing attractive football and for their good sportsmanship. Despite applying several times and being a popular choice for the job, he was never appointed England manager and has been dubbed the "greatest manager England never had".

Clough played as a striker for Middlesbrough and Sunderland, scoring 251 league goals in 274 matches; he remains one of the Football League's highest goalscorers. He won two England caps. He entered management after his playing career was ended by a serious injury at the age of 29. As a manager, Clough was closely associated with Peter Taylor, who served as his assistant manager at several clubs in the 1960s, 1970s and 1980s. He is also remembered for giving frequent radio and television interviews in which he made controversial remarks about players, other managers and the overall state of the game. In 1965, he took the manager's job at Fourth Division Hartlepools United and appointed Peter Taylor as his assistant, the start of an enduring partnership that would bring them success at several clubs over the next two decades. In 1967, the duo moved on to Second Division Derby County who, in 1968–69, were promoted as Second Division champions and, three years later, crowned champions of England for the first time in the club's history. In 1973, they reached the semi-finals of the European Cup. By this point, Clough's relationship with chairman Sam Longson had deteriorated; he and Taylor resigned.

An eight-month spell in charge of Third Division club Brighton & Hove Albion followed, before Clough (without Taylor) returned north in the summer of 1974 to become manager of Leeds United. This was widely regarded as a surprise appointment, given his previous outspoken criticism of the Leeds players and their manager Don Revie. He was sacked after just 44 days in the job, but within months, he had joined Second Division Nottingham Forest, where he was re-united with Taylor in the summer of 1976. In 1977, Forest were promoted to the top flight and the following season won the league title (the first in the club's history), making Clough one of only four managers to have won the English league with two clubs. Forest also won two consecutive European Cups (in 1979 and 1980) and two League Cups (1978 and 1979), before Taylor retired in 1982. Clough stayed on as Forest manager for another decade and won two more League Cups (1989 and 1990) and reached the FA Cup final in 1991, but could not emulate his earlier successes. Forest were relegated from the Premier League in 1993, after which Clough retired from football.

Brian Howard Clough was born on Thursday, 21 March 1935 at 11 Valley Road, an inter-war council house in Grove Hill, Middlesbrough, North Riding of Yorkshire, He was the sixth of nine children of a local sweet shop worker, later sugar boiler and then manager. The eldest, Elizabeth, died on 11 February 1927 of septicaemia at the age of three. When talking of his childhood he said he "adored it in all its aspects. If anyone should be grateful for their upbringing, for their mam and dad, I'm that person. I was the kid who came from a little part of paradise." On his upbringing in Middlesbrough, Clough claimed that it was "not the most well-appointed place in the world, but to me it was heaven". "Everything I have done, everything I've achieved, everything that I can think of that has directed and affected my life – apart from the drink – stemmed from my childhood. Maybe it was the constant sight of Mam, with eight children to look after, working from morning until night, working harder than you or I have ever worked."

Clough failed his Eleven-plus examination and attended Marton Grove Secondary Modern School. He later admitted in his autobiography, Walking on Water, that he had neglected his lessons in favour of sport, although at school he became Head Boy. He also said that cricket, rather than football, was his first love as a youngster, and that he would have rather scored a test century at Lord's than a hat-trick at Wembley. He left school in 1950 without any qualifications, to work at ICI and did his national service in the RAF Regiment between 1953 and 1955.

"I played with some great players and I think Cloughie was a great finisher. He was a powerful lad and both his timing and positional play were excellent. You placed him in that bracket as Roger Hunt, but in more modern terms he was very similar to Mark Hughes when it came to volleying. The one thing, right or wrong, that he insisted on was that he played down the middle because, he reasoned, that was where he scored, not out wide so why should I run wide. That was his only failing. When he played for England he wanted people to play like Boro did but when you've got people around like Bobby Charlton and Jimmy Greaves, you can't tell those guys I will just stop in the middle."

Clough played for Great Broughton Juniors and, while working for ICI, Billingham Synthonia (scoring three goals in four games) before his national service in the RAF between 1953 and 1955. He combined playing football in the forces, though he was never selected for the RAF National team, and playing for the Boro third team when on leave.

Following this, he became a prolific striker for his home town club Middlesbrough since his debut in the 1955–56 season and an impressive 1956–57 season now as starter, scoring 204 goals in 222 league matches for Boro, including 40 or more goals in four consecutive seasons, being Division Two topscorer in two of them: 1958–59 and 1959–60. However, Clough also regularly submitted transfer requests since the 1957–58 season and had a tense relationship with some of his fellow players. He was especially irked by Boro's leaky defence, which conceded goals as regularly as he scored them. In the 1960–61 season after a 6–6 draw against Charlton Athletic, Clough sarcastically asked his teammates how many goals they would have to score in order to win a match. He also publicly accused some of his teammates of betting against the team and deliberately letting in goals. While at Middlesbrough, Clough became acquainted with goalkeeper Peter Taylor, with whom he would later form a successful managerial partnership at several clubs.