In the game of contract bridge, a strong club system is a set of conventions that uses an opening bid of 1-Club as an artificial, unlimited-strength opening. Compare this with Standard American, which used the opening of 2 Clubs for a similar purpose.

Generally, because of the lower level, the strong 1-Club opening can be assigned a minimum strength much lower than would be advisable for Standard American's 2-Club opening. Commonly, the strong 1-Club will promise 16 or more high card points. All other bids would therefore be limited to a maximum of 15 high card points.

The generally acknowledged strength of the strong club systems is accuracy in uncontested slam-strength auctions, because the bidding starts at such a low level when opener has a fairly strong hand. The generally acknowledged weakness of such systems is the fact that the opponents can aggressively overcall the 1-Club bid to deprive the stronger opponents of their bidding room.

The original strong club system was the Vanderbilt Club, invented in the 1920s by the man who invented contract bridge itself, Harold Vanderbilt.

Precision Club is another example of a strong club system.