A shelf unit has a modular, interlocking design and eliminates the need for hardware components. The shelf unit includes first and second side pieces each including first and second rails and first, second, and third rungs extending between the first and second rails. First and second shelf-supporting connectors attach with the first rungs of the first and second side pieces and the second rungs of the first and second side pieces, respectively, via interlocking slots. A first shelf is positioned atop the first shelf-supporting connector and a second shelf is positioned atop the second shelf-supporting connector.