Status lingkungan hidup di Indonesia memiliki tiga permasalahan utama yakni persoalan sampah, kualitas air, dan permasalahan lahan. Ketiga hal ini dapat diatasi dengan melakukan pengelolaan lingkungan. Jenis upaya dan teknik pengelolaan lingkungan belum dikenal secara luas oleh masyarakat terkhusus bagi remaja generasi penerus di sekolah. Pengenalan upaya dan teknik pengelolaan lingkungan ada dalam fase E Kurikulum Merdeka tetapi untuk pengenalan nya masih kurang dan dibutuhkan sumber tambahan. Penggunaan Website dapat dijadikan alternatif untuk mengenalkan upaya dan teknik pengelolaan lingkungan di sekolah. Penelitian ini bertujuan untuk mengembangkan suplemen belajar berupa website dan menguji produk sehingga produk layak untuk digunakan. Penelitian ini merupakan penelitian pengembangan dengan menggunakan model ADDIE (Analysis, Design, Development, Implementation, Evaluation). Sampel pada penelitian ini, yaitu peserta didik kelas XI. Hasil penelitian berupa website Kenal Kelola Lingkungan yang berhasil dikembangkan dan layak digunakan untuk pembelajaran karena memperoleh kategori valid berdasarkan penilaian para ahli, serta kategori sangat baik pada keterbacaan pengguna yakni peserta didik dan guru Biologi ***** Indonesia's environmental status faces three major challenges: waste, water quality, and land issues. These three issues can be addressed through environmental management. Environmental management efforts and techniques are not yet widely recognized by the public, especially the next generation of youth in schools. The introduction of environmental management efforts and techniques is included in Phase E of the Merdeka’s Curriculum, but this introduction is still lacking and additional resources are needed. The use of websites can be an alternative way to introduce environmental management efforts and techniques in schools. This study aims to develop a learning supplement in the form of a website and test the product to ensure its feasibility. This research is a developmental study using the ADDIE (Analysis, Design, Development, Implementation, Evaluation) model. The sample in this study were 11th grade students. The results of the research are in the form of the website "Kenal Kelola Lingkungan” which was successfully developed and is suitable for use for learning because it obtained a valid category based on expert assessments, as well as a very good category in terms of user readability, namely students and Biology teachers.