The ruling party in a parliamentary system is the party or coalition of the majority in parliament. Within a parliamentary system, the majority in the legislature also controls the executive branch of government, thus leaving no possibility of dueling parties concurrently occupying the executive and legislative branches of government, such as in an American style presidential system where the party of the president does not necessarily also have a legislative majority.

Ruling party is also used to describe the party of one-party states, such as the Communist Party of China in China.

执政党