A two-part bucket stabilizing apparatus for use with cylindrical joint compound buckets or the like during the mixing of the contents thereof includes a horizontal base member containing an opening for receiving the bottom of the bucket, and a support member having a first edge portion pivotally connected with the base member, and a remote edge portion containing a semi-circular recess. The support member is pivotally operable from an initial horizontal position upwardly and inwardly toward a clamping position above the base portion in which the wall of the semi-circular recess is in clamping engagement with the outer circumferential wall surface of the bucket.