Favorite son is a political term.

• At the quadrennial American national political party conventions, a state delegation sometimes nominates a presidential candidate from the state, or less often from the state's region, who is not a viable candidate in the view of other delegations, and votes for this candidate in the initial ballot. The technique allows state leaders to negotiate with leading candidates in exchange for the delegation's support in subsequent ballots.

Serious candidates usually, but not always, avoided campaigning in favorite sons' states. If a party's leader in a state, usually the governor, was unsure of whom to support, as the favorite son the state party could avoid disputes. Conversely, a party leader who has chosen a candidate might become a favorite son to keep other candidates' campaigns out of the state, or prevent a rival local politician from becoming a favorite son. The favorite son may explicitly state that the candidacy is not viable, or that the favorite son is not a candidate at all. The favorite son may hope to receive the vice-presidential nomination, Cabinet post or other job, increase support for the favorite son's region or policies, or just the publicity from being nominated at the convention.

The technique was widely used in the 19th and early 20th centuries. Since nationwide campaigns by candidates and binding primary elections have replaced brokered conventions, the technique has fallen out of use, as party rule changes in the early 1970s required candidates to have nominations from more than one state.

• A politician whose electoral appeal derives from their native state, rather than their political views is called a "favorite son". For example, in the United States, a presidential candidate will usually win the support of their home state(s).
• Especially in parliamentary systems, a "favorite son" is a party member to whom the party leadership is likely to assign a prominent role, for example, Paul Martin while Jean Chrétien was the Prime Minister of Canada, or Gordon Brown while Tony Blair was the Prime Minister of the United Kingdom.