Advice and consent is an English phrase frequently used in enacting formulae of bills and in other legal or constitutional contexts. It describes either of two situations: where a weak executive branch of a government enacts something previously approved of by the legislative branch or where the legislative branch concurs and approves something previously enacted by a strong executive branch.

The concept serves to moderate the power of one branch of government by requiring the concurrence of another branch for selected actions. The expression is frequently used in weak executive systems where the head of state has little practical power, and in practice the important part of the passage of a law is in its adoption by the legislature.

In the United Kingdom, a constitutional monarchy, bills are headed:

BE IT ENACTED by the King's most Excellent Majesty, by and with the advice and consent of the Lords Spiritual and Temporal, and Commons, in this present Parliament assembled, and by the authority of the same, as follows:

This enacting formula emphasizes that although legally the bill is being enacted by the British monarchy (specifically, by the King-in-Parliament), it is not through his initiative but through that of Parliament that legislation is created.

In Singapore, a parliamentary republic with the President of Singapore being the head of state, the President has a number of powers. Some of the President's powers may only be exercised "on the advice of the Cabinet". In this context, "advice of the Cabinet" means that the President must not only consider the Cabinet's advice but also act in full accordance with it, with no ability to exercise discretionary power.

In the United States, "advice and consent" is a power of the United States Senate to be consulted on and approve treaties signed and appointments made by the president of the United States to public positions, including Cabinet secretaries, federal judges, officers of the armed forces, United States attorneys, ambassadors, and other smaller offices. This power is also held by several state senates, which are consulted on and approve various appointments made by the state's chief executive, such as some statewide officials, state departmental heads in the governor's cabinet, and state judges (in some states).

The term advice and consent appears twice in the United States Constitution, both times in Article II, Section 2, Clause 2. First, the term is used in reference to the senate's role in the signing and ratification of treaties. Then, it is used to describe the Senate's role in the nomination and confirmation process for federal appointees.