Legal separation (sometimes "separate maintenance," "divorce a mensa et thoro," or "divorce from bed-and-board") is a possible step towards divorce under the laws of many countries. A couple is legally separated only if the couple has successfully petitioned a court to recognize their separation; simply living apart does not constitute separation for these purposes.

Legal separation does not automatically lead to divorce. The couple may reconcile, in which case they need do nothing in order to remain married. If they do not reconcile, and wish to divorce after the statutory time period, they must file for divorce explicitly.

A period of legal separation may constitute grounds for divorce and some countries require some period of legal separation before a divorce can take effect (e.g. Spain, Ireland and Italy). Some states within the United States require separation before divorce. The required period of separation before filing for divorce varies.

In many jurisdictions that do not recognize the concept of spousal rape, a man cannot be prosecuted for the rape of his legally separated wife.