Abstract: Preferred top-loading adjustable weight kettlebell systems described herein preferably include a kettlebell base and at least one top-loading nesting weight. The kettlebell base preferably include a main body and a handle, the main body having a substantially convex upper surface, the handle upwardly extended from the main body. The at least one top-loading nesting weight preferably has a handle opening defined therein. The at least one top-loading nesting weight may have a substantially convex upper surface and a substantially concave lower surface. The at least one top-loading nesting weight is preferably loadable onto the kettlebell base by insertion of the handle through the handle opening. Preferred top-loading adjustable weight kettlebell systems may include a two-part securing mechanism for securement between the kettlebell base and the at least one top-loading nesting weight.