A solicitor is a lawyer who traditionally deals with most of the legal matters in some jurisdictions. A person must have legally defined qualifications, which vary from one jurisdiction to another, to be described as a solicitor and enabled to practise there as such. For example, in England and Wales a solicitor is admitted to practise under the provisions of the Solicitors Act 1974. With some exceptions, practising solicitors must possess a practising certificate. There are many more solicitors than barristers in England; they undertake the general aspects of giving legal advice and conducting legal proceedings.

In the jurisdictions of England and Wales and in Northern Ireland, in the Australian states of New South Wales, Victoria, and Queensland, Hong Kong, South Africa (where they are called attorneys) and the Republic of Ireland, the legal profession is split between solicitors and barristers (called advocates in some countries, for example Scotland), and a lawyer will usually only hold one of the two titles. However, in Canada, Malaysia, New Zealand, Singapore and the remaining Australian states and territories, the legal profession is now for practical purposes "fused", allowing lawyers to hold the title of "barrister and solicitor" and practise as both. Some legal graduates will start off as one and then also qualify as the other. In the United States, the barrister–solicitor distinction never existed.

Regulation of the profession in Australia varies from state to state. Admission to practise is state-based, although mutual recognition enables a practitioner admitted in any state or territory to practise in any other state or territory, or at the federal level. In all states and territories, solicitors have unlimited rights of audience and so can, at least in theory, practise as a solicitor, barrister or both. The formal names for admitted solicitors differs between jurisdictions. For example, in some jurisdictions, they are admitted as "legal practitioners", while in other jurisdictions they are admitted as "solicitors and barristers".

The extent to which the profession is "fused" in practice varies from state to state. In general, however, there is a separate bar with its own professional body composed of those practitioners who adopt the traditional barrister's model of practice, i.e. working in chambers and undertaking advocacy work. In some states, call to the bar requires different or additional training. A proportion of the other practitioners would practise as both solicitors and barristers, while still others would practise primarily or exclusively as solicitors. The relative sizes of the latter two categories differ from jurisdiction to jurisdiction.

Before the creation of the Supreme Court of Judicature under the Supreme Court of Judicature Act 1873, solicitors practised in equity in the Court of Chancery, attorneys practised in the common law courts, and proctors practised in the "civil law" (based on Roman law) of the ecclesiastical courts. The monopoly of the proctors in family, inheritance and admiralty law had been removed in 1857–1859, and the 1873 reforms further fused all three branches of the profession. After 1873 the offices of "attorney" and "proctor" disappeared as terms relating to legally qualified persons, being replaced by "Solicitor of the Supreme Court of Judicature" (subsequently "of the Supreme Court of England and Wales"), except for the unique government offices of Queen's (or King's) Proctor (now called "HM Procurator-General", a title generally held by the Treasury Solicitor), and Attorney-General. Since the replacement of the judicial aspect of the House of Lords with a new Supreme Court of the United Kingdom (in 2009), separate from the existing Supreme Court of Judicature of England and Wales, the full title of a solicitor is "Solicitor of the Senior Courts of England and Wales".

The term "attorney" is however still used under English law to refer to someone legally appointed or empowered (who may but need not be legally qualified) to act for another person. Currently, the term is most commonly used to refer to someone so appointed under a "power of attorney". This may be a "general power of attorney" under section 10 of the Powers of Attorney Act 1971; a lasting power of attorney may be granted under the provisions of the Mental Capacity Act 2005. Some practitioners in specialist professions, notably intellectual property, are also referred to as attorneys, for example registered patent attorneys, which is a separate qualification from that of a solicitor.

In the English legal system, solicitors traditionally dealt with any legal matter, including conducting proceedings in courts, although solicitors were required to engage a barrister as advocate in a High Court or above after the profession split in two. Minor criminal cases are tried in magistrates' courts, which constitute by far the majority of courts. More serious criminal cases still start in the magistrates' court and may then be transferred to a higher court.

The majority of civil cases are tried in county courts and are almost always handled by solicitors. Cases of higher value (£100,000 or above) and those of unusual complexity are tried in the High Court, and barristers, as the other branch of the English legal profession, have traditionally carried out the functions of advocacy in the High Court, Crown Court and Court of Appeal.