While there is a substantial research literature on Western ‘foreign fighters’ – those young men and women from Europe, North America, Australia and elsewhere who traveled to Syria and Iraq, from around 2011–2017, to join jihadist groups engaged in combat – there is a dearth of comparative studies examining the backgrounds of these fighters. National variations in the levels of recruitment have been measured and samples examined to determine the demographics of these fighters, indicating some national variations in who went, how, and maybe why. More fulsome comparative data is needed, however, to detect and measure such differences to gain insight into the factors conditioning the radicalization of these foreign fighters. Calling on original and unique datasets, this study presents the results of a comparative analysis of Canadian and Swedish foreign fighters. In each case the findings are compared with other domestic jihadists as well to delineate if those drawn to fight in Syria and Iraq differ. Clear differences emerge in the basic demographics of these national samples, highlighting some empirical and interpretive issues in need of further analysis.