Context:55 Cancri hosts five known exoplanets , most notably the hot super-Earth 55 Cnc e , which is one of the hottest known transiting super-Earths . Aims : Due to the short orbital separation and host star brightness , 55 Cnc e provides one of the best opportunities for studying star-planet interactions ( SPIs ) . We aim to understand possible SPIs in this system , which requires a detailed understanding of the stellar magnetic field and wind impinging on the planet . Methods : Using spectropolarimetric observations , and Zeeman Doppler Imaging , we derive a map of the large-scale stellar magnetic field . We then simulate the stellar wind starting from the magnetic field map , using a 3D MHD model . Results : The map of the large-scale stellar magnetic field we derive has an average strength of 3.4 G. The field has a mostly dipolar geometry , with the dipole tilted by 90 ^ { \circ } with respect to the rotation axis , and dipolar strength of 5.8 G at the magnetic pole . The wind simulations based on this magnetic geometry lead us to conclude that 55 Cnc e orbits inside the Alfvén surface of the stellar wind , implying that effects from the planet on the wind can propagate back to the stellar surface and result in SPI . Conclusions :