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Abstract Tides are an important factor shaping the sea ice system in the Arctic Ocean by altering vertical heat fluxes and advection patterns. Unfortunately, observations are sparse, and the analysis of tides is complicated by the proximity of wind-driven inertial oscillations to the semidiurnal frequencies. Furthermore, computational costs typically prohibit the inclusion of tides in ocean models, leaving a significant gap in our understanding. Motivated by summer observations showing elevated downward surface heat fluxes in the presence of tides, we analyzed simulations carried out with an eddy-permitting coupled ice–ocean model to quantify the impact of tidal effects on Arctic sea ice. In line with previous studies, we find an overall decrease in sea ice volume when tides are included in the simulations, associated with increased vertical mixing and the upward flux of heat from deeper layers of the Arctic Ocean, but this sea ice volume decrease is less pronounced than previously thought. Surprisingly, our simulations suggest that in summer, Arctic sea ice area is larger, by up to 1.5%, when tides are included in the simulations. This effect is partly caused by an increased downward surface heat flux and a consequently lower sea surface temperature, delaying sea ice melting predominantly in the Siberian Seas, where tides are moderately strong and the warm Atlantic Water core is located relatively deep and does not encroach on the wide continental shelf. Here, tidally enhanced downward heat flux from the surface in summer can dominate over the increased upward heat flux from the warm Atlantic Water layer. Significance StatementThis study sheds light on the complex and understudied role of tides in Arctic sea ice dynamics. By utilizing advanced computer models, our research uncovers that, contrary to common expectations, tides contribute to a seasonal increase in sea ice area by up to 1.5% in summer. This effect is attributed to enhanced advection of sea ice into the Siberian Seas and a local increase in downward heat flux reducing sea surface temperatures, thereby delaying sea ice melting in this region. Our findings challenge prevailing notions about the negative impact of tides on sea ice and highlight the importance of incorporating tidal impacts in ocean models to improve predictions of Arctic sea ice changes, key for our understanding of both Arctic and global climate dynamics.