In contract bridge, the Stayman convention is a convention used to find a four-four trump fit in a major suit after someone opens the bidding with a bid of 1 No Trump. It may also be modified for use after an opening 2 No Trump or a strong 3 No Trump bid.

The opening bidder's partner, the responder, bids 2 Clubs to ask the no trump bidder to name a four card major suit if he has one. By using the Stayman convention the responder takes control of the bidding since a description of the opener's hand is already known within a limited range. Usually, the responder has at least one four-card major himself, and is looking for a possible 4-4 fit, but he may also have other motives in using the convention. It is generally understood that playing in an 8-card major fit is often superior to playing in no trump, hence the logic of this convention. The opener has the following rebids available:

2 diamonds - denies having a four card major

2 hearts - promises a four card heart suit, may also have a four card spade suit

2 spades - promises a four card spade suit, denies having a four card heart suit

In the most basic variation of the convention, the responder normally continues as follows:

2 notrump - invitational, no 4-4 major suit fit apparent

3 notrump - game values, no 4-4 major suit fit apparent

3 of opener's major - invitational, 4-4 major suit fit

4 of opener's major - game values, 4-4 major suit fit

After an invitational bid, the opener will pass with minimum values (for the agreed opening notrump range) or bid game with maximum values. For example, if the opening 1NT range is agreed as 15-17 HCP, then an invitational responder hand will have a good 8 or 9 HCP. Opener will pass with 15 HCP, bid game with 17 HCP, and use judgement with 16 HCP.

When the responder continues in notrump and the opener holds four cards in both majors, the opener should correct the contract to spades at the appropriate level. (It can be inferred that responder holds four spades, else he would not have any reason to bid Stayman with an invitational or better hand.)

Some partners may by agreement also use the 2 No Trump, 3 hearts or 3 spades rebids after Stayman to show the same card distributions but with the high card point being the maximum for the 1 No Trump bid. Other rebids by the opener are undefined.

The bid has no relation to the 2 Club bidder's club suit. It is a convention, because its meaning is derived from a pre-arranged agreement rather than a natural interpretation of the bid. Like any bridge convention, there are many variations on the theme, and differences of opinion as to the details of its use. It is one of the most widely-used conventions in the game.

While the convention is named after the person who first wrote about it, Samuel Stayman, it was actually invented by his partner, George Rapee.

Jacoby transfers are often used to complement Stayman.

Another variation of Stayman is Puppet Stayman.