Public bodies, such as local government councils, cannot sue for defamation. People employed by, or elected to, government authorities may, however, be able to sue in defamation if their personal reputation has been damaged by a publication.

General groups (such as lawyers, doctors, people from a particular country, university students or the staff of a certain shop) cannot sue for defamation, unless the group is so small that a person could say she or he was readily identifiable. For example, defamatory words referring to senior management of a company might sufficiently identify a number of people so that they can all bring actions in defamation.

Any non-profit group or organisation that has a recognised legal status (such as a trade union or an incorporated association) can sue and be sued for defamation, but a group that is not a legal entity (such as an unincorporated association or a social club) cannot sue for damages or to protect its good name, even if its individual members can prove that they were defamed by a statement made about the group. Again, if the group is small enough to identify the individual members of the group and the statement affects their personal reputation, the individuals in the group may sue.

If an executive of an unincorporated club publishes a defamatory letter about a person, the person defamed can sue each of those involved in the publication of the letter. If a person says an unincorporated club is inefficient and corrupt, the people running the unincorporated club may be able to sue as separate individuals (if they are identifiable and their reputation has been affected), but in neither case can the unincorporated club itself sue or be sued. A group such as this, with no legal identity apart from its members, cannot sue to vindicate its reputation, see COMMUNITY ORGANISATIONS.

A company can be defamed, though only small or not-for-profit corporations can sue for defamation. These are called 'excluded corporations' under the Act. Excluded corporations are those which do not have the object of financial gain for members or corporators or which employ fewer than 10 people and which are not an associated entity of another corporation [s 9(2)]. An employee is defined as any individual (including an independent contractor) who is engaged in the day to day operations of the corporation other than as a volunteer, and is subject to the control and direction of the corporation [s 9(6)]. Part-time employees are taken into account as a fraction of their full-time equivalent. Companies, like people, have reputations that can be damaged. However, although companies can claim damages for loss of reputation (provided they have suffered reputational harm which has caused, or is likely to cause serious financial loss), they can get nothing for injury to feelings. It is said they have no feelings.

Persons or bodies who suffer damage from publications who cannot sue for defamation may be able to sue for injurious falsehood (see Other Remedies). To succeed in an action for injurious falsehood it must be shown that there has been a monetary loss suffered and that the statement is false and was made dishonestly or within intent to cause loss and without any lawful justification.

It is not possible to defame a dead person [see Defamation Act 2005 (SA) s 10]. However, costs for proceedings may be awarded if a plaintiff dies part way through proceedings, and the Court finds it is in the interests of justice to do so [s 10(2)].