This research aimed at investigating the effect of a hybrid collaborative project- based course on developing 21st century skills, academic achievement, and attitude towards PBL among Gen Z junior English major student teachers at the Faculty of Education, Mansoura University. A random sample of third year English major students (N= 230) were the target participants. They were divided alphabetically to two groups, and randomly assigned to an experimental and a control group. The quasi-experimental approach using a pre- post administration to two independent groups design was adopted for achieving the purpose of the current study. Instruments designed and used were a 21st Century Skills assessment Inventory, an achievement test and an attitude towards PBL scale. T-test for both dependent and independent samples was used for data analysis. Results proved that the experimental group's post levels in 21st Century skills and attitude towards PBL were significantly higher than the control group. The experimental group outperformed the control group in academic achievement, although the differences were not so great. These results confirmed that the use of hybrid collaborative PBL had considerable potential in enhancing 21st century skills, academic achievement, and attitude towards PBL among EFL major junior students