Arsenal manager Arsene Wenger has said that King should be allowed a chance to resume his career upon his release, but Allardyce has urged the general public not to view King as a typical footballer.
Allardyce said: 'Players make a huge contribution in this country. If you ask (PFA chief executive) Gordon Taylor about how much charity work they do, it would answer your question.
'I spoke to him (Taylor) the other day and told him he really should put that out in the public domain, particularly at a time like this.
'We've got one isolated case which is very disappointing indeed, but overall, Premier League footballers and most of the footballers throughout the Football League do a huge amount for their communities and this country.'
Wenger has claimed that King will find employment within the game once he has served his sentence.
He said: 'I believe that you have justice and, it's not my justice, it is the justice that England has decided to apply to his case.
'When he (King) has paid his sentence, of course you would consider signing someone like that.
'Otherwise you would never forgive anybody anything. When he has paid his sentence, some clubs, if they want, they will take him.'
King's conviction has led to criticism of the behaviour of richly-rewarded footballers, but Allardyce claims that the matter should be viewed as an isolated incident.
PFA chief executive Taylor has rejected claims that the players' union failed to support King by insisting the organisation is under no obligation to stand by players who break the law.
An appeal is planned by King, but with the 29-year-old's agent, Tony Finnegan, criticising the PFA's lack of support, Taylor has responded by claiming that the player did not seek union assistance.
Taylor said: 'The PFA does not represent players when they have broken the law and been convicted on non-footballing matters.
'Nevertheless, should any member with anger management or other issues approach us for assistance, we are always happy to provide that assistance through the Sporting Chance Clinic as has been the case with other such high profile cases.
'We have never been approached by Marlon King or his representatives for such assistance and are therefore unable to rely on any information other than the conviction and sentencing (on Thursday).'
Meanwhile, Roy Hodgson revealed Fulham terminated their interest in King in 2008 when they discovered he had served a jail sentence.