Air memiliki peran penting bagi setiap makhluk hidup untuk memenuhi kebutuhan esensial. Asupan cairan dalam hal ini air minum menjadi sangat penting bagi tubuh manusia, maka perlu diperhatikan kualitas air minum sesuai standar yang telah ditetapkan. Saat ini, banyak penyelenggara air minum isi ulang mendapatkan ijin operasi untuk memproduksi air minum bagi masyarakat. Untuk menjaga kualitas air minum yang dikonsumsi masyarakat, dilakukan pengawasan secara berkala baik secara internal maupun eksternal. Penelitian ini bertujuan untuk mengidentifikasi adanya bakteri Escherichia coli pada salah satu merek air minum isi ulang yang berada di Yogyakarta yang bernama Khaira. Uji mikrobiologis dilakukan dalam penelitian ini. Data diperoleh melalui pemeriksaan air isi ulang menggunakan metode Most Probable Number (MPN). Hasil uji MPN menunjukkan tidak terdeteksi Escherichia coli pada semua sampel air. Kualitas air minum isi ulang yang diproduksi “Khaira” Yogyakarta berdasarkan uji identifikasi Escherichia coli memenuhi persyaratan batas cemaran mikroba.The identification of escherichia coli contains in ”Khaira” Yogyakarta refill waterWater has an important role for every living thing to meet essential needs. Fluid intake, in this case drinking water, is very important for the human body, so it is necessary to pay attention to the quality of drinking water according to established standards. Currently, many refill drinking water providers have obtained operating licenses to produce drinking water for the community. To maintain the quality of drinking water consumed by the community, periodic monitoring is carried out both internally and externally. This study was aimed to identify the Escherichia coli contains in one of the refill waters in Yogyakarta namely, Khaira. The microbiological test was used in this study. This research was conducted by identifying Escherichia coli in refill drinking water. The data was obtained by checking the refill water using the Most Probable Number (MPN) method. The MPN test results showed no Escherichia coli was detected in all water samples. The quality of refill drinking water produced by “Khaira” Yogyakarta based on the Escherichia coli identification test meets the requirements for microbial contamination limits.