最小外置矩形 (minimum bounding rectangle, MBR)，也有译为最小边界矩形，最小包含矩形，或最小外包矩形。最小外置矩形是指以二维坐标表示的若干二维形状（例如点、直线、多边形）的最大范围，即以给定的二维形状各顶点中的最大横坐标、最小横坐标、最大纵坐标、最小纵坐标定下边界的矩形。这样的一个矩形包含给定的二维形状，且边与坐标轴平行。最小外置矩形是最小外置框(minimum bounding box)的二维形式。

The minimum bounding rectangle (MBR), also known as bounding box or envelope, is an expression of the maximum extents of a 2-dimensional object (e.g. point, line, polygon) or set of objects within its (or their) 2-D (x, y) coordinate system, in other words min(x), max(x), min(y), max(y). The MBR is a 2-dimensional case of the minimum bounding box.