A McKenzie Friend assists an unrepresented litigant in a court of law in England and Wales, Hong Kong, Northern Ireland, the Republic of Ireland, New Zealand, Canada and Australia by prompting, taking notes, and quietly giving advice. They need not be legally trained or have any professional legal qualifications.

The right to a McKenzie Friend was established in the 1970 case of McKenzie v McKenzie.

A 2005 Court of Appeal case, In the matter of the children of Mr O'Connell, Mr Whelan and Mr Watson, clarified the law in this area. The result of the appeal has legitimised the use of McKenzie Friends in the family court and allowed unrepresented litigants to disclose confidential court papers to the McKenzie Friend.

Family Courts in England and Wales allow fee charging McKenzie Friends, who may charge for their services, including the giving of legal advice. A recent report by the Legal Service Consumer Panel found that fee charging McKenzie Friends were a net benefit. The report stated, “They should be viewed as providing valuable support that improves access to justice in the large majority of cases.”