Abstrak : UMKM Dusun 01 Purwodadi merupakan usaha mikro kecil dan menengah di bidang makanan ringan seperti untir-untir, kelanting, dan keripik singkong. Pemasaran produk masih dilakukan secara manual melalui toko ke toko, brosur, media sosial, dan perbincangan antarorang, sehingga ruang lingkup penjualan terbatas. Tujuan penelitian ini adalah merancang dan membuat sistem informasi berbasis website untuk pemasaran produk makanan ringan pada UMKM Dusun 01 Purwodadi. Metode perancangan yang digunakan adalah SDLC (System Development Life Cycle) dengan pendekatan Object Oriented Programming (OOP), sedangkan pengujian dilakukan menggunakan Black Box Testing dan Beta Testing. Hasil penelitian menunjukkan bahwa sistem yang dikembangkan mampu memberikan informasi dan pelayanan jual beli secara online yang dapat diakses kapan saja. Sistem menyediakan menu untuk mengirim bukti pembayaran transfer bank, kemampuan pengisian data penjualan, serta pembuatan bukti transaksi secara online. Meski demikian, sistem masih memiliki kekurangan, yaitu proses pembayaran masih bergantung pada upload bukti transfer. Disarankan agar penelitian selanjutnya mengintegrasikan sistem dengan payment gateway agar pembayaran dapat dilakukan langsung melalui website. Kata Kunci : UMKM, Website, SDLC, Object Oriented Programming, Abstract: UMKM Dusun 01 Purwodadi is a micro, small, and medium enterprise (MSME) in the food industry, producing snacks such as twisted crackers, kelanting, and cassava chips. Product marketing is still done manually through store-to-store sales, brochures, social media, and word-of-mouth, resulting in limited market reach. This study aims to design and develop a web-based information system for marketing snack products at UMKM Dusun 01 Purwodadi. The development method used is the System Development Life Cycle (SDLC) with an Object Oriented Programming (OOP) approach, while testing is carried out using Black Box Testing and Beta Testing. The results show that the developed system can provide online information and sales services accessible anytime. The system includes features for uploading bank transfer proof, entering sales data, and generating transaction receipts online. However, the system still has limitations, as the payment process relies on uploading transfer proof. It is recommended that future research integrate a payment gateway so that transactions can be completed directly through the website. Keywords: MSME (Micro, Small, and Medium Enterprises), Website, Waterfall, Object Oriented Programming,