A bread loaf retainer and slicing knife guide comprising a horizontal support surface and a surrounding vertical rim, the support surface having a plurality of spaced, upwardly projecting, bread loaf penetrating protrusions to retain the end of a loaf of bread in fixed position on the support surface, the vertical rim extending above the support surface a specific amount substantially equal to the desired bread slice thickness, and having an upper edge forming a coplanar guide for engagement by a bread knife in continuous contact therewith to cut a slice of uniform thickness. In one embodiment, a ring telescopically interfits with the rim and has a height greater than the rim to extend above the rim, and has an upper edge forming a guide surface for the bread knife to allow slicing of a bread slice to a uniform thickness. In another embodiment, a second vertical rim extends downwardly from the support surface a different amount than the first rim and has a second guide surface for a bread knife, the support surface also having a second set of projecting bread loaf penetrating protrusions generally parallel to the second vertical rim such that by inverting the bread loaf retainer, and holding the end of a bread loaf thereon, a uniform slice of bread of different thickness can be cut.