Using the 353-GHz polarization observations by the Planck satellite we characterize the magnetic field in the Orion-Eridanus super-bubble, a nearby expanding structure that spans more than 1600 square degrees in the sky. We identify a region of both low dispersion of polarization orientations and high polarization fraction associated with the outer wall of the superbubble identified in the most recent models of the large-scale shape of the region. We use the Davis-Chandrasekhar-Fermi method to derive plane-of-the-sky magnetic field strengths of tens of mu G toward the southern edge of the bubble. The comparison of these values with existing Zeeman splitting observations of HI in emission suggests that the large-scale magnetic field in the region was primarily shaped by the expanding superbubble.