A vehicle body framework structure includes an elongated hollow framework member and a reinforcement member disposed within the hollow framework member, the reinforcement member including a first contact portion that contacts a first internal face of an opposing pair of internal faces of the framework member, a second contact portion that contacts a second internal face of the opposing pair of internal faces, and a coupling portion that couples the first contact portion to the second contact portion. At least one slit is formed in at least the second contact portion and the coupling portion of the reinforcement member, the slit extending from an end portion on the second internal face side of the reinforcement member toward the first internal face side of the reinforcement member and having a depth that is greater than or equal to one fourth of a spacing between the pair of internal faces.