Barnardo's director Martin Crewe made the claim as he said MSPs had been shocked by the scale of the evidence the charity presented to them.
It came after Holyrood's Public Petitions Committee issued a call for refuges for young Scots at risk of child sexual exploitation (CSE), and for all schools to offer workshops on sexual attitudes and internet safety, after an investigation into the evidence.
MSPs also said police should make more use of orders to restrict the liberty of those who are deemed to pose a threat of sexual harm or exploitation to children.
Mr Crewe said: "The sexual exploitation of children is a sickening crime and I think the committee has been shocked by the evidence Barnardo's and others have presented.
"From our experience, child sexual exploitation is going on in all the cities and possibly in the towns as well."
Sexual exploitation of children is where a person under 18 is given something - such as food, housing, drugs, gifts or money - as a result of engaging in sexual activities.
MSPs carried out an inquiry into current efforts to tackle CSE and concluded that the response across Scotland has been patchy.
Their main recommendation to ministers is to develop a strategy to tackle the problem and commission research into its scale.
The committee considered the issue after a petition was lodged by the charity Barnardo's Scotland as part of its Cut Them Free campaign. Barnardo's called for a greater focus after frontline workers expressed concern that authorities were too complacent.
Mr Crewe says exploitation including the kind of group grooming exposed in English towns and cities is happening here too.
The committee's report says CSE has remained largely unreported in Scotland, partly as young people do not always recognise themselves as victims. In some exploitative relationships with adults, children are persuaded what is happening is normal.
Convener David Stewart MSP said "Our committee has heard some difficult and at times challenging evidence about child sexual exploitation in Scotland.
"We received powerful first hand accounts. Although there is a lot of positive work being done, it can be piecemeal. It lacks the clear leadership and coordination needed to tackle effectively the sexual exploitation of our children.
"There is also the very real danger CSE will continue to be a hidden problem in Scotland, which is why research must be carried out to establish the scale of the problem and how best to shape services to address it."
The report says an investigation should be held into why Scotland's only refuge for young runaways was closed. It also says schools should work to challenge sexual stereotypes, such as girls being passive and boys aggressive within relationships. It calls for work with young men to tackle attitudes to sexual coercion.
Meanwhile, the committee says Police Scotland should adopt a "high commitment" to disrupting the activity of perpetrators.
NSPCC Scotland welcomed the committee's call for a strategy. Matt Forde, National Head of Service for NSPCC Scotland, described it as a "critical step forward". He added: "There is no doubt child sexual exploitation is a significant issue for young people, and one which requires a coordinated, national solution.
A Police Scotland spokesman said: "The protection of children from abuse or neglect is a very high priority for Police Scotland.
"All agencies involved are committed to ensuring that all incidents of sexual exploitation involving children or young persons are professionally and thoroughly investigated."
He urged anyone with concerns about youngsters being at risk to contact police.