掌玺大臣（Lord Keeper of the Privy Seal），在国务重臣（Great Officers of State）中位列第五，在枢密院议长之下，但在掌礼大臣（Lord Great Chamberlain）之上。此职并无特定负责事务，是英国的闲职（Sinecure）之一。掌玺大臣起初负责君主的私玺（与国玺相对，国玺由**负责）。出任此职者，往往同时是内阁阁员。

掌玺大臣是英国政府最古老的职位之一，在今日已无特定功能。此职的用途类似于不管部大臣。二次大战结束后，出任掌玺大臣者通常兼任上议院领袖（Leader of the House of Lords）或下议院领袖。

The Lord Privy Seal (or, more formally, the Lord Keeper of the Privy Seal) is the fifth of the Great Officers of State in the United Kingdom, ranking beneath the Lord President of the Council and above the Lord Great Chamberlain. The office is one of the traditional sinecure offices of state. Originally, its holder was responsible for the monarch's personal (privy) seal (as opposed to the Great Seal of the Realm, which is in the care of the Lord Chancellor). Today, the holder of the office is invariably given a seat in the Cabinet of the United Kingdom.