Brassicaceae is the name of a medium-sized and economically important family of flowering plants (angiosperms), informally known as the mustards, mustard flowers, the crucifers, or the cabbage family.

The name Brassicaceae is derived from the included genus Brassica. Cruciferae, an older name, meaning "cross-bearing", describes the four petals of mustard flowers, which resemble a cross; it is one of eight plant family names without the suffix '-aceae' that are authorized alternative names (according to ICBN Art. 18.5 and 18.6 Vienna Code); thus both Cruciferae and Brassicaceae are used.