Venue deals with the locality of a lawsuit, specifically the question of which court or courts with proper jurisdiction may hear a specific suit. At the most basic level, venue is the location where a case should be heard. Proper venue generally is determined by the location in which the events giving rise to the legal action took place. Further, the proper venue is the location from which a jury may be drawn to try the legal action.
Both plaintiffs and defendants can waive objections to venue at the time of trial. Additionally, potential plaintiffs may waive their right to sue in certain venues through a contract that contains a valid and reasonable forum selection clause. The defendant usually makes a change of venue request, but the prosecutor may request a venue change or the court may sua sponte invoke a venue change as well.
Venue is a distinct concept from jurisdiction. Where jurisdiction deals with the authority of a court to hear a particular case, venue is concerned with the geographical location of the court where an action is commenced.
In the United States, venue will either be a county (for state court) or a district or division (for federal court). Under United States law, unlike personal jurisdiction, there is no constitutional requirement for proper venue in order to have a valid judgment.
Generally in state court actions, civil actions must be started where either the plaintiff (or defendant) resides or does business, or where the cause of action arose. In the alternative, if real property is at issue, the action must be brought where the real property is situated. In criminal cases, proper venue is the locality where the crime was committed.
28 U.S.C. § 1391 outlines the general application of venue in federal court. Under §§ 1391(a-b), proper venue for civil actions will be a judicial district where any of the defendants reside, a judicial district wherein a substantial part of the action or property giving rise to the claim occurred or is located, a judicial district in which any of the defendants are subject to personal jurisdiction in diversity jurisdiction cases or in which any defendant can be found in cases of non-diversity jurisdiction cases.
For corporations, under § 1391(c), residence for venue purposes is defined as any location where the corporation is subject to a court's personal jurisdiction. An alien, however, can be sued in any district under § 1391(d).
28 U.S.C. § 1404 also prescribes the process for changing venue in federal proceedings. A district court has the discretion to allow for a change of venue, for the convenience of the parties and witnesses or in the interests of justice, to any district or division where the proceeding might have been originally brought. In other words, a district court can allow for a change of venue only to another district or division of proper venue - parties cannot seek to change venue to a location lacking the proper foundation for venue to hear the matter.
'Interests of justice' is open to interpretation but often involves factors including efficient use of judicial resources, avoiding unnecessary waste and expense, convenience to parties and witnesses, familiarity of the court with the state law to be applied, level of congestion of the respective courts and avoidance of inconsistent adjudications. A change of venue may also be proper in the case of high-profile matters where it may be impossible to find fair and unbiased jurors in the given venue because of a high level of publicity of the events giving rise to the action.
The U.S. Code provides additional special rules governing venue in 28 U.S.C. §§ 1392-1413. For instance, special statutes set different rules for admiralty, patent, and interpleader lawsuits and lawsuits in which the United States is a party.
In civil cases, the proper recourse for challenging venue is a motion to dismiss under Federal Rules of Civil Procedure 12(b)(3).  A motion to dismiss for improper venue is a 'waivable defense,' meaning that improper venue must be pled in the defendant's initial response to the complaint or else it will be waived. Statutes usually provide that a judgment rendered by a state court is valid even if venue is improper, so failure to timely plead improper venue will not later support an overturning a ruling.
A case transferred by removal from a state court to a federal court goes to the federal court in the district where the state action was started.