Apparatuses and methods for guiding endoluminal devices through body lumens. Several embodiments of the present technology, for example, are directed to flexible tubular sheaths or sleeves configured to provide a smooth, low friction pathway through which an endoluminal device can be delivered to a target site in a human patient. In one embodiment, for example, a flexible sheath or sleeve may comprise an elastomeric body and a plurality of structural elements carried by the elastomeric body. The structural elements may be oriented co-axially along the flexible sheath. The elastomeric body is configured to expand radially to accommodate passage of the endoluminal device through the flexible sheath or sleeve to the target site in the patient.