In this study we assessed the representation of the sea surface salinity (SSS) and liquid freshwater content (LFWC) of the Arctic Ocean in the historical simulation of 31 CMIP6 models with comparison to 39 Coupled Model Intercomparison Project phase 5 (CMIP5) models, and investigated the projected changes in Arctic liquid and solid freshwater content and freshwater budget in scenarios with two different shared socioeconomic pathways (SSP2‐4.5 and SSP5‐8.5). No significant improvement was found in the SSS and LFWC simulation from CMIP5 to CMIP6, given the large model spreads in both CMIP phases. The overestimation of LFWC continues to be a common bias in CMIP6. In the historical simulation, the multi‐model mean river runoff, net precipitation, Bering Strait and Barents Sea Opening (BSO) freshwater transports are 2,928 ± 1,068, 1,839 ± 3,424, 2,538 ± 1,009, and −636 ± 553 km³/year, respectively. In the last decade of the 21st century, CMIP6 MMM projects these budget terms to rise to 4,346 ± 1,484 km³/year (3,678 ± 1,255 km³/year), 3,866 ± 2,935 km³/year (3,145 ± 2,651 km³/year), 2,631 ± 1,119 km³/year (2,649 ± 1,141 km³/year) and 1,033 ± 1,496 km³/year (449 ± 1,222 km³/year) under SSP5‐8.5 (SSP2‐4.5). Arctic sea ice is expected to continue declining in the future, and sea ice meltwater flux is likely to decrease to about zero in the mid‐21st century under both SSP2‐4.5 and SSP5‐8.5 scenarios. Liquid freshwater exiting Fram and Davis straits will be higher in the future, and the Fram Strait export will remain larger. The Arctic Ocean is projected to hold a total of 160,300 ± 62,330 km³ (141,590 ± 50,310 km³) liquid freshwater under SSP5‐8.5 (SSP2‐4.5) by 2100, about 60% (40%) more than its historical climatology.