Crown Steward and Bailiff of the Manor of Northstead is an "office under the Crown" in the United Kingdom, appointment to which disqualifies its holder from sitting as a Member of Parliament. It is used to allow MPs to effectively resign their seats, a move which is formally prohibited. A number of offices have been used for this purpose, but only the Manor of Northstead and the Chiltern Hundreds are used today.

The office is only nominally paid. Generally, it is held until the next time it is used to effect the resignation of an MP. The Manor of Northstead is usually used alternately with the Chiltern Hundreds, which makes it possible for two members to resign at exactly the same time. Where more than two MPs resign at a time, as for example happened when 15 Ulster Unionist MPs resigned on December 17 1985, the resignations are in theory not simultaneous but instead spread throughout the day, with each member holding one of the offices for a short time. The holder can subsequently be re-elected to Parliament.

In 1623 a rule was declared that said that members of Parliament were given a trust to represent their constituencies, and therefore were not at liberty to resign them. In those days, Parliament was relatively weaker, and service was sometimes considered a resented duty rather than a position of power and honour. However, an MP who accepts an "office of profit" from the Crown was obliged to leave his post, it being feared that his independence was compromised if he be in the King's pay. Therefore, the legal fiction was invented that the MP who wished to quit applied to the King for the post of "steward of the Manor of Northstead", an obsolescent office of negligible duties and scant profit, but an office in the King's gift nonetheless.

The office was first used as a pretext for resignation in 1844.