The equitability theorem for matroids says that if the ground set of a matroid can be partitioned into $k$ bases, then the elements of any prescribed subset can be distributed almost equally among the bases. In our paper Weighted Equitability and Matroid-Constrained Discrepancy, we prove a weighted analogue: for arbitrary nonnegative weights, there is a decomposition into bases such that the total weights of any two bases differ by at most the weight of the heaviest element, and such a decomposition can be found in strongly polynomial time. The result has applications to matroid-constrained scheduling and fair division, and leads to more general discrepancy bounds for rounding under matroid constraints.