<p><i>Illex argentinus</i> is an important cephalopod species widely distributed in Patagonian waters of the southwest Atlantic Ocean. Its distribution is influenced by various environmental factors, as well as mesoscale eddies which are important marine dynamic processes that regulate the environment in this region. However, the mechanism by which eddies affect the distribution of <i>I. argentinus</i> remains unclear. This study analyzed the relationship between the distribution of <i>I. argentinus</i> and both cyclonic (CE) and anticyclonic (AE) eddies, with focus on environmental shifts in sea surface temperature (SST), water temperature at 200&#xa0;m depth (T_200m), and chlorophyll-a concentration (Chl-a). We constructed a Habitat Suitability Index (HSI) model to explore how eddies regulate the distribution of <i>I. argentinus</i>. The results showed that <i>I. argentinus</i> abundance was negatively correlated with SST and T_200m, but positively correlated with Chl-a. There was a significantly higher abundance of squid in CEs than in AEs which was mainly distributed on the western periphery side of CEs. Squid abundance showed differing trends in each eddy type between January and April, with an initial increase and then a decrease within CEs, and an overall gradual increase within AEs. The HSI in CEs was significantly higher than that in AEs, and high-HSI areas coincided with the distribution pattern of high abundance of <i>I. argentinus</i>. Therefore, this study indicates that eddies in Patagonian waters have a significant impact on the abundance and distribution of <i>I. argentinus</i>, and the environmental conditions characterized by lower temperatures and higher productivity in CEs are more conducive to yield suitable habitat of this species.</p>