Bonetti played seven times for England, but mainly served the team as a back-up to Gordon Banks. Bonetti was part of the winning England squad for the 1966 FIFA World Cup, but did not play. He belatedly received a winners' medal in 2009, after the Football Association led a successful campaign for non-playing members of the squad to be recognised. After Banks fell ill before the 1970 FIFA World Cup quarter-final, Bonetti played as England lost 3–2 to West Germany.
In 1948 Bonetti's family moved from London to Worthing on the Sussex coast. His parents ran a cafe on the seafront next to the Worthing Dome. Bonetti shone at an early age, playing for Worthing.
Chelsea signed him from the Reading youth team after his mother had written to then manager Ted Drake, requesting that he give her son a trial. Whilst a Chelsea junior, Bonetti made five appearances for Croydon Amateurs in the Surrey Senior League thanks to youth team coach Albert Tennant who was also coaching Croydon at that time. He made his first team debut in 1960 and a few weeks later helped the Chelsea youth side win the FA Youth Cup. From the 1960–61 season onwards, he was Chelsea's first choice goalkeeper, a position he held more or less constantly for the next nineteen years. Chelsea were relegated in Bonetti's second full season, which saw the appointment of Tommy Docherty as manager. Bonetti emerged as a key figure in a talented young side which included Bobby Tambling, Terry Venables, John Hollins and Barry Bridges. The team went into the penultimate match of the season needing to beat promotion rivals Sunderland to have a chance of going up. Chelsea won 1–0, with Bonetti making a brilliant last minute save to deny George Mulhall and maintain his side's promotion chances; a 7–0 win over Portsmouth secured instant promotion back to the First Division.
The new Chelsea side challenged for honours during the 1960s, with Bonetti a key figure throughout, although more often than not the team narrowly missed out. Chelsea won the League Cup in 1965 with a 3–2 aggregate victory over Leicester City. Leicester put Chelsea under heavy pressure in the second leg at Filbert Street, but an inspired performance from Bonetti helped secure a 0–0 draw for his side and thus the trophy. For most of the same season, Chelsea were on course to add both the league title and the FA Cup but ultimately missed out. They were beaten by Liverpool in the FA Cup while the title challenge was ended with a few games left after a bust-up between Docherty and several of his first-team players – though not Bonetti – meaning that a much-weakened team was fielded in a key match against Burnley, in which Bonetti conceded six goals.
Bonetti played in every game of Chelsea's Fairs Cup run the following season, putting in a series of impressive displays against the likes of AS Roma, AC Milan and FC Barcelona, though the side were eventually knocked out in the semi-finals, as they were in the FA Cup for the second consecutive year. The signing of Alex Stepney at the end of that season briefly threatened his position as Chelsea's first choice goalkeeper and he considered putting in a transfer request, but Stepney ultimately played only one game for the club and was sold to Manchester United a few months later. Chelsea eventually reached an FA Cup final in 1967, where they faced Tottenham Hotspur, but the team got outplayed on the day and Bonetti could do little to stop Spurs winning 2–1.
That was the closest he came to winning another trophy with Chelsea until 1970, by which time Docherty had been succeeded by Dave Sexton. In 1970, Chelsea again reached the FA Cup final and this time faced reigning league champions Leeds United. Over the two fiercely contested games, Bonetti had what was perhaps the finest moment of his playing career. Chelsea were outplayed for large spells in the first final at Wembley and he made a series of crucial saves to help them emerge with a 2–2 draw. Shortly into the replay at Old Trafford, his left knee was badly injured after a challenge from Leeds' Mick Jones. He returned to the field after treatment, but was effectively playing on one leg for the rest of the match and was powerless to stop Jones scoring the opener a few minutes later. In spite of the injury, and being targeted by the Leeds forwards, he made crucial saves throughout the match, denying both Peter Lorimer and Terry Cooper, and resisted more pressure from Leeds after Chelsea had taken the lead in extra time to help secure a 2–1 win. Such were Bonetti's performances that season, he was voted runner-up in the FWA footballer of the Year awards.
A year later, the team added the UEFA Cup Winners' Cup after another replayed win in the final, this time over Spanish giants Real Madrid in Athens. Chelsea took a 2–0 lead in the replay, but Real dominated for much of the second half and it was another inspired performance from Bonetti, who had missed a large part of that season through injury, which helped them hold on for a 2–1 win.
That was his last trophy with the club, although they narrowly missed out on more in the following years, losing in the 1972 League Cup final to Stoke City and in the semi-finals of the same competition to Norwich City a year later. Financial and disciplinary problems within the club prevented them from building on their success.
Bonetti left on a free transfer in 1975, joining the St. Louis Stars of the North American Soccer League (NASL). That year, he played 21 games for the side and helped them top the Central Division that summer and reach the play-off semi-finals.
He then returned to Chelsea, where his experience proved invaluable in helping new manager Eddie McCreadie's young side gain promotion in 1976–77. Two years later, in May 1979, he played his final game for Chelsea, a 1–1 draw with Arsenal, having made a total of 729 appearances for the club in nineteen years – only Ron Harris has made more – and kept over 200 clean sheets. He conceded one goal or less in two-thirds of his games for Chelsea.
Bonetti's international career was somewhat unfortunate. He emerged in an era of talented English goalkeepers and thus faced stiff competition for a place in the side, particularly from Ron Springett and Gordon Banks, and later Peter Shilton, which limited him to just seven caps. He was a member of England's successful 1966 World Cup squad, but didn't make an appearance. His career with the England national side is also largely remembered for one match – the 1970 FIFA World Cup quarter-final against West Germany in Mexico, when he was thrust into the starting line-up as a late replacement for Banks, who was suffering from a stomach problem. During the match England let slip a 2–0 lead and lost 3–2 after extra time, with Bonetti one of the scapegoats, although he could be reasonably faulted for only one of the three goals conceded. That game was his only World Cup appearance. He conceded one goal in his other six international matches.
In the 1966 World Cup final only the 11 players on the pitch at the end of the 4–2 win over West Germany received medals. Following a Football Association led campaign to persuade FIFA to award medals to all the winners' squad members, Bonetti was presented with his medal by Gordon Brown at a ceremony at 10 Downing Street on 10 June 2009.
After leaving Chelsea, Bonetti moved to the Isle of Mull where he became a postman. While living in Scotland, he briefly came out of retirement to play several games for Dundee United as understudy to Hamish McAlpine. Following his retirement from playing, Bonetti moved into coaching and had spells with Chelsea and the England national side, as well as working with Kevin Keegan at Newcastle United, Fulham and Manchester City. During his time as a Chelsea coach, he was persuaded to play two games for Isthmian League Division 2 side, Woking, including an FA Cup debut in a 1–0 win over Football Conference side Weymouth. At one time he held the record for the most appearances for a single club by a goalkeeper, but was overtaken in the 1990s by Portsmouth's Alan Knight.
Since 2005, Bonetti made several appearances for an Old England XI in various charity games, notably against celebrity sides, usually coming on for the last 10 minutes of each game.ChelseaSecond Division promoted: 1962–63, 1976-77League Cup: 1964-65FA Cup: 1969-70UEFA Cup Winners' Cup: 1971FA Youth Cup: 1959-60St. Louis StarsNASL Central Division: 1975EnglandWorld Cup: 1966
Totals include one Charity Shield appearance in 1970–71.
Bonetti died on 12 April 2020, aged 78, following a long illness.