<p>Halloysite nanotubes (HNTs) loaded with the corrosion inhibitor benzotriazole (BTA) have been utilized to enhance the corrosion resistance of epoxy coatings. To improve BTA loading capacity, the HNTs were thermally treated and modified with Zn²⁺ ions. Furthermore, to control the release of BTA, Zn²⁺ ions were also used to form Zn–BTA complexes at the tube ends, acting as end stoppers. Thermogravimetric analysis showed that the combination of heat treatment and Zn²⁺ modification significantly increased the BTA loading capacity of HNTs, reaching up to 15.5 wt%. UV–Vis spectroscopy demonstrated that, under neutral conditions, the additive with Zn²⁺ end stoppers exhibited a much slower BTA release rate compared to the non-end-stoppered system, while the release rate significantly increased in acidic environments. The corrosion protection performance of epoxy coatings containing the BTA-loaded, Zn²⁺-modified HNTs was evaluated using electrochemical methods and salt spray testing. Results indicated that a 3 wt% additive loading provided the best corrosion resistance, significantly outperforming conventional epoxy coatings. Additionally, salt spray tests on commercial zinc-rich epoxy coatings with scribed defects revealed that the inclusion of the BTA-loaded, Zn²⁺-modified HNTs imparted active corrosion inhibition. These findings suggest that the prepared benzotriazole-loaded zinc ion-modified HNTs are a promising candidate for incorporation into epoxy coatings to improve the anticorrosion performance of carbon steel.</p>