Dame Vera Baird has backed a new law, which would give victims of crime more rights.
The former Redcar MP is now the Victims' Commissioner for England and Wales. She says a "change of culture" is "long overdue".
Dame Vera told the PA news agency: "The point is to bring about a long-overdue change of culture whereby the criminal justice system starts to look after victims properly.
"At the moment we have a situation where a lot of victims say the process in the courts makes them feel worse than the crime did, and they're dropping out quite quickly... due to how they've been treated."
A review of the court process made 34 recommendations for the government, including:
A requirement to keep victims better updated on the progress of investigations
A statutory right for sexual assault victims to be given free legal representation
Court-ordered compensation to be paid to the victim, and later recouped from the defendant, by the court rather than "drip-fed" on a weekly basis.
It is very bad if somebody is so poorly treated that they don't feel that the state is supporting them when they have been wronged in this way.
"It's terribly bad for them but it's also terribly bad for us as a civilised society if we don't give victims the support they need."
Last year, a Victims' Commissioner survey was carried out.
of people felt that victims were given enough support through the court process.
A separate piece of research by Dame Vera also suggested that just 14% of respondents agreed with the notion that survivors of rape and sexual offences can get justice by reporting an incident to the police.
Currently, all victims of crime have a set of rights set out in the Victims' Code, with a new version coming into effect in April.
The Conservatives pledged to enshrine this code into law in their manifesto, but legislation is yet to be introduced in Parliament.
Dame Vera said she hopes her report will be of interest to Prime Minister Boris Johnson, who she described as being "extremely interested in victims' rights".
She added: "The Ministry of Justice has promised a victims' law... it emerges (in manifestoes) and disappears.
"It would make a massive difference to victims if it was done.
"Victims are participants from start to finish, but they are currently treated more like bystanders.
"We must recognise justice cannot be delivered without victims and our justice system needs to reflect this.
"I'm calling for a redefinition of the victim that moves beyond treating them as simply an onlooker or maybe a witness, but as a recognised participant, with statutory rights to be informed, supported and to be able to make informed choices.
"This does not in any way undermine the rights of the defendant and does not make them a party to proceedings, or a decision-maker, but it does confirm victims as active contributors in their own right to the criminal justice process."