The Sailor project, developed by Sea AI Lab and the Singapore University of Technology and Design, introduces a revolutionary suite of open language models designed specifically for Southeast Asian languages, including Indonesian, Thai, Vietnamese, Malay, and Lao. Ranging from 0.5B to 7B parameters, these models are meticulously trained on a massive corpus encompassing over 200 billion tokens across seven key languages, aiming to bridge the linguistic gap in AI technologies. Sailor's inclusive approach not only promises enhanced performance in diverse linguistic scenarios but also sets a new standard for AI's applicability across the rich cultural tapestry of Southeast Asia. Available for both research and commercial use, Sailor models are accessible on HuggingFace, marking a significant step towards making AI technologies truly global and inclusive.