The NPCC said 98 per cent of those identified as victims are male and clubs spanning all tiers of the game have been 'impacted'.
Police have warned that because of the huge number of complaints officers may take longer that usual to respond - but insisted that they will make contact.
National Police Chiefs' Council lead for Child Protection, Chief Constable Simon Bailey said: 'Allegations received by police forces across the country are being swiftly acted upon.
'We are also liaising closely with the Football Association to ensure all relevant information they hold is shared to inform investigations moving forward.
'We continue to urge anyone who may have been a victim of child sexual abuse to report it by dialling 101, or contacting the dedicated NSPCC helpline, regardless of how long ago the abuse may have taken place. We will listen and treat all reports sensitively and seriously. Anyone with any information regarding child sexual abuse is also urged to come forward.
'When allegations are reported it enables police to assess whether there are current safeguarding risks and ensure that appropriate action is being taken to prevent children being abused today.
'As the number of calls being received across the service is higher than usual, it may take longer than normal for an officer from a local force to make contact to follow up from the initial call. Please be assured that the information provided will be taken seriously and acted upon.'
The Metropolitan Police has said a team of specialist officers from its sexual offences, exploitation and child abuse command would probe allegations of 'non-recent' crimes - but refused to say which clubs it was investigating.
An NSPCC spokesman said: 'These shocking numbers now identified by police reveal the deeply disturbing extent of abuse that has been going on within football.
'Our football hotline, launched with the support of the FA, saw a staggering surge in calls in its first week and anyone who wants to contact us can continue to do so in confidence, with the knowledge they will be listened to and supported.'
It comes as clubs across the country have been implicated in a growing child sex abuse scandal gripping the sport, with Southampton facing the prospect of potential legal action by former youth players.
Scotland Yard said its team would work with Operation Hydrant, the over-arching nationwide investigation into historical child sex abuse.
Detective Chief Superintendent Ivan Balhatchet said: 'We take all the allegations we receive very seriously and they will be dealt with sensitively.
'Anyone who has been a victim of sexual abuse, whatever the circumstances, or has any relevant information should contact their local police or the NSPCC.'
There are 13 London-based clubs in the four professional English football leagues.
One of them, QPR, was drawn into the controversy on Tuesday.
The Championship club said it was aware of historical child abuse allegations involving former chief scout Chris Gieler, who died in 2004, and would co-operate with any investigations.
At the weekend Chelsea 'apologised profusely' to former striker Gary Johnson, who was sexually abused while a youth-team player in the 1970s.
One man has formally instructed a law firm after alleging that he was abused when he was a teenager training with Southampton's youth set-up.
It is understood others who were part of the south-coast club's youth system in the mid-1980s are also talking to Southampton-based BL Claims Solicitors about possibly representing them.
The unnamed man who has formally instructed the firm claims the first incident of abuse he suffered took place during a youth tournament in Sweden.
The man, who remained at Southampton for two years after signing a youth-team training contract, now suffers from severe mental health problems, lawyers said.
The disclosure of potential legal action came in the week that ex-Saints and England forward Matt Le Tissier told the BBC he was given a 'very, very wrong' naked massage by a coach at Southampton.
Southampton have previously said they are 'committed to working together' with Hampshire Police to investigate any historical child sex abuse allegations.
Solicitor Malcolm Johnson, of BL Claims, said: 'The problem in the sports world is that child abusers thrive in an environment where children are scared to speak up for fear that they will lose their place in a team.
'At the time when these incidents are alleged to have occurred, child safeguarding regulations were also less stringent than they are today, making it easier for abuse to go undetected.
'Any perpetrators who are found guilty of abuse will have not only groomed and abused their victims in the most catastrophic way but also abused the trust of their families and the rest of the football community.'
Meanwhile, double Olympic champion Dame Kelly Holmes is convinced allegations of child sex abuse will soon start emerging in other sports.
The 46-year-old, who won gold at 800 metres and 1500m at the Athens Olympics in 2004, told ITV's Good Morning Britain: 'I absolutely believe it's going to come out, probably in swimming, gymnastics, athletics.
'Because you hear those things done in the past, and I've heard of people that have said it, that are just friends or...
'Since this all came out to light, other people are now talking. I don't think this is a closed door at the moment.'
FOOTBALL'S ABUSE ALLEGATIONS: EVENTS SO FAR
November 16: In a harrowing interview, former Crewe youth player Andy Woodward tells how he was sexually abused as a boy in the 1980s by a former coach and scout. The 43-year-old, who went on to play for Bury, waived his right to lifelong anonymity to speak out.
November 22: A second Crewe player, Steve Walters, tells The Guardian about his abuse by the same coach, while former Spurs, Liverpool and England forward Paul Stewart speaks out about his treatment by a different youth coach in the 1970s. Cheshire Police confirms 'a number of people' have come forward with allegations in the wake of Woodward's interview and Professional Footballers' Association chief executive Gordon Taylor tells Press Association Sport the number of former footballers to contact the union with similar claims is in 'double figures'.
November 23: Former England and Manchester City forward David White becomes the fourth former footballer to go public as a victim of sexual abuse.
November 24: Crewe director of football Dario Gradi releases a statement saying he knew nothing about the allegations at his club until a coach was convicted in 1994. Manchester City announce they are 'undertaking a thorough investigation' into allegations of wrongdoing in their youth system in the 1970s and 1980s. England captain Wayne Rooney publicises a new, confidential, 24-hour helpline set up by the FA and the NSPCC - the child protection charity later reveals it received 50 calls in its first few hours.
November 25: Two more former Manchester City youth players tell the BBC's Victoria Derbyshire programme about the abuse they suffered as boys, while police in Hampshire, London and Northumbria confirm they too are investigating new allegations.
November 26: After mounting pressure, League Two side Crewe announce the club is to launch an independent review into how they dealt with child abuse allegations in the 1980s and 1990s.
November 27: The Football Association announces that Kate Gallafent QC will lead an independent review of its response to the allegations in the past.
November 29: A former coach is charged with offences between 1981 and 1985 against a boy aged under 14. Chelsea say in a statement that they have retained a law firm to carry out an investigation concerning an one of their 1970s employees, who is now dead. A spokesman said the club would provide the FA with 'any relevant information arising out of the club's investigation'. FA chairman Greg Clarke tells reporters this is one of the game's 'biggest' crises, and former darts world champion Eric Bristow is dropped by Sky Sports after a series of insensitive tweets about football's sex abuse victims.
November 30: Former Newcastle player Derek Bell says he wanted to kill his abuser George Ormond, who was convicted in 2002, while Stewart names former Blackpool youth coach Frank Roper, who died in 2005, as the man who abused him.
December 1: Two former Southampton players are interviewed by BBC South on the sexual abuse they endured from an unnamed coach, Newcastle player David Eatock says he was abused by Ormond aged 21 and NSPCC chief executive Peter Wanless says the helpline had 860 calls in its first week.
December 2: Southampton contact Hampshire Police following information supplied to the club in relation to historical child abuse within football. Meanwhile, the Daily Mirror reports that former Chelsea youth-team player Gary Johnson signed a confidentiality agreement with the club in 2015 in return for £50,000 after he alleged he had been abused by chief scout Eddie Heath, who is now dead, in the 1970s. With many questioning the ethics of such an agreement, the club waived it, allowing Johnson to speak out.
December 3: Chelsea issue a lengthy statement. In it, they 'apologise profusely' to Johnson, who was sexually abused and 'suffered unacceptably' while a youth-team player at the London club in the 1970s. The Blues say they have 'no desire to hide any historic abuse we uncover from view' and are 'fully committed to ensuring the safety and well-being of all children and young people who are in our care or attending our premises'.
December 5: Woodward, Walters and ex-Manchester City youth-team player Chris Unsworth launched The Offside Trust - a new, independent trust that will 'fight for justice' and support victims. Walters said he and Woodward also wanted an apology while Edward Smethurst, a lawyer representing victims, claimed there are still individuals in the game who 'need further investigation' and that gagging orders have been used by 'a number' of clubs.
December 6: The FA announces its independent review will be led by Clive Sheldon QC instead of Kate Gallafent QC 'in the light of the increased scope of the review'.
December 8: The Metropolitan Police has said a team of specialist officers from its sexual offences, exploitation and child abuse command would probe allegations of 'non-recent' crimes - but refused to say which clubs it was investigating.
December 9: The National Police Chiefs' Council said that officers have had 639 cases referred to them from the NSPCC's helpline or direct calls to police.
