In today's interconnected world, marked by technological progress, global mobility and international cooperation, Higher Education Institutions (HEI) have a responsibility to provide students with the essential skills required to thrive in such a dynamic environment. With the increasing significance of 21st-century skills in determining employability, educational institutions worldwide are thus in pursuit of methods to enhance students' readiness for the demands of the modern world. This pursuit extends beyond merely supporting the development of essential skills and qualifications for professional success -it is also about empowering students to become engaged and capable citizens who can adeptly manage change and uncertainty, about fostering active learning methods and supporting the development of robust interpersonal skills.In the academic year 2021/2022, still amidst the effects of a global pandemic that brought enormous disruptions to every level of education, two departments of the University of Aveiro, Portugal, came together to challenge English as a Foreign Language (EFL) students to engage in a collaborative activity which aimed, above all, to prepare future Business Communication professionals for the global challenges ahead. The resulting "Global Skills for the 21st Century: Language and Intercultural Competence" project was designed as a learner-centred activity, based on collaboration and research work, with the main purpose of developing students' English language and intercultural communication (IC) skills, as well as fostering the development of evermore relevant transferable skills, such as communication and collaboration, creativity, critical thinking and problem-solving, adaptability and resilience, among others. As will be evidenced, the project design aligns with frameworks, guidelines, and recommendations established by various international organisations, namely the United Nations, the UNICEF, the OECD, the European Union, the Council of Europe, and the World Economic Forum.The objective of this paper is twofold: on the one hand, to present this online-based collaborative classroom activity developed by two groups of undergraduate students. On the other hand, the authors seek to provide answers to the questions: "To what extent do such collaborative learning approaches contribute to the enhancement of language and IC skills, as well as the simultaneous development of essential 21st-century skills?" and "What is students' self-perceived development in terms of social skills and cognitive/functional skills?". To provide an answer to these questions, a mixed-methods approach was employed, utilising an online questionnaire and the analysis of students' assignments (research posters). The results indicate that the project positively influenced students' cognitive, social/emotional, and digital skills. The assessment of research posters demonstrates the application of language and IC skills in producing high-quality outputs. These findings highlight the value of implementing student-centred pro...