To identify suitable fishing areas for Argentine shortfin squid （Illex argentinus） in the Southwest Atlantic and to compare the applicability and differences of different types of fishing-vessel activity data in habitat suitability index （HSI）-based fishing-ground prediction， this study selected the Southwest Atlantic as the study area. Automatic identification system （AIS） data and visible infrared imaging radiometer suite （VIIRS） boat detection （VBD） data from January to May during 2017–2023 were used as experimental datasets to represent squid-jigging fishing effort. These data were combined with multi-source and multi-depth marine environmental variables. A boosted regression tree （BRT） model was used to screen monthly key environmental variables and determine their weights. Based on the weighting results， a weighted arithmetic mean model （WAMM） and a weighted geometric mean model （WGMM） were constructed to predict suitable fishing areas from January to May 2024. The prediction results were validated using AIS data， VBD data， and fishery production statistics in 2024. The results showed that the BRT model was able to identify the key environmental factors affecting the distribution of fishing activity. The cross-validated area under the curve （AUC） of the AIS-based BRT model ranged from 0.91 to 0.96， while that of the VBD-based BRT model ranged from 0.81 to 0.83. The variable-selection results from the BRT models constructed using the two types of data indicated that seawater temperature， seawater salinity， and sea surface height were the key environmental factors influencing the fishing activity distribution of I. argentinus. HSI model validation showed that the average proportions of suitable habitats under the WAMM based on AIS and VBD data were 81.01% and 71.15%， respectively， both higher than those under the WGMM. From January to May 2024， highly suitable habitats were mainly distributed in a belt-like pattern along the outer Patagonian Shelf and the shelf-slope zone， with localized high-value areas occurring to the north and northeast of the Falkland Islands. The results suggest that the BRT-weighted WAMM is more suitable for identifying suitable fishing areas for I. argentinus. AIS data are advantageous for characterizing the spatial continuity and overall distribution pattern of fishing activity at the monthly scale， whereas VBD data show higher coverage of high-catch and high-catch per unit effort （CPUE） areas during the middle and late fishing season. This study provides a methodological reference for fishing-ground identification， dynamic monitoring， and the joint application of multi-source fishing-vessel activity data for I. argentinus in the Southwest Atlantic.