<p>Southern Ocean heat uptake during 1958–2014 is investigated using high- and low-resolution simulations with two climate models against multiple observational datasets. Temperature trends are decomposed into heave and spice components to identify the mechanisms driving ocean heat uptake. All model simulations broadly reproduce the observed warming pattern, although they differ in spatial detail and underlying processes. The subsurface warm tongue north of 55°S is driven by heave-related warming across both versions of both models. This warming is linked to wind-induced vertical displacement of isopycnals. High-resolution model simulations tend to capture a deeper penetration of the warming as more consistent with observations than its low-resolution counterpart. South of 55°S, however, none of the model configurations reproduce the observed surface cooling. Instead, both high- and low-resolution versions simulate surface warming associated with spiciness changes. Such discrepancy is tied to sea ice biases, as models of both resolutions simulate a declining trend in sea ice extent while observations display an increase. Differences in the spiciness component between resolutions also reveal localized variability, driven by spatial differences in surface fluxes. These variations influence surface warming along isopycnals across the Southern Ocean. Overall, model resolution plays an important role in modulating the contributions from heave and spiciness. However, neither resolution consistently outperforms the other. Each exhibits strengths and limitations depending on latitude, depth, and the processes involved.</p>