Staphylococcus aureus is a leading cause of catheter-related bloodstream infections and endocarditis. Both involve (i) biofilm formation, (ii) exposure to fluid shear, and (iii) high rates of dissemination. We found that viscoelasticity allowed S. aureus biofilms to resist detachment due to increased fluid shear by deformation, while remaining attached to a surface. Further, we report that S. aureus microcolonies moved downstream by rolling along the lumen walls of a glass flow cell, driven by the flow of the overlying fluid. The rolling appeared to be controlled by viscoelastic tethers. This tethered rolling may be important for the surface colonization of medical devices by nonmotile bacteria.