ISO 690 is an ISO standard governing bibliographic references in different kinds of documents, including electronic documents. This international standard specifies the bibliographic elements that need to be included in references to published documents, and the order in which these elements should be stated.

ISO 690 governs bibliographic references to published material in both print and non-print documents. The current version of the standard was published in 2021 and covers all kinds of information resources, including monographs, serials, contributions, patents, cartographic materials, electronic information resources (including computer software and databases), music, recorded sound, prints, photographs, graphic and audiovisual works, and moving images.

ISO 690 ranks among a number of ISO standards that bear on academic publishing, such as ISO 214 [Wikidata], which establishes rules for abstracts; ISO 2145, which deals with numbering of divisions and subdivisions of written documents; and ISO 2014 and ISO 3166, which, respectively, establish the correct use of dates and country codes.

Punctuation and style are not part of the standard; largely, the standard governs content rather than presentation.

ISO 690 prescribes a referencing scheme with a fixed order of bibliographic elements in which the publication date appears after the "production information" of place and publisher, but it allows an exception for the Harvard system, in which the date appears after the creator name(s).

The standard allows for three citation methods:

The first edition of the ISO 690 standard was published in 1975.

The second edition, published in 1987, includes elements specific to patent citations, rendering obsolete the ISO 3388:1977 standard devoted to them.