This study investigates the relationship between the WhatsApp group, an instant messenger application as a community of practice platform (knowledge management, regular interactions, ease of using technology, and sense of belonging) and English for Specific Purposes (ESP) learners' leadership and higher-order thinking (HOT) skills. The current study also examines how participation in the community of practice through the WhatsApp group can enhance leadership and HOT skills for male and female learners. 197 ESP learners participated in the five-point Likert scale questionnaire. The SPSS-AMOS analysis showed that knowledge management, regular interaction, and a sense of belonging significantly enhance learners' leadership and HOT skills. The results also showed that male learners increased their leadership skills while female learners excelled in the HOT skills by the WhatsApp community of practice. This study has significant educational implications, particularly in emphasizing essential measures when developing an ESP curriculum to prepare learners for their future careers.