Beta-glucuronidase-positive (GUD+) Shiga toxin-producing Escherichia coli (STEC) O157:H7 was isolated from both an asymptomatic woman and uncooked deer meat in her possession in Hokkaido, Japan. The phenotypic and genotypic characteristics of the two isolates were identical or closely related, indicating probable transmission of the deer isolate to the woman. Moreover, several other GUD+ STEC O157:H7 strains investigated belonged to the distinct atypical GUD+ STEC O157:H7 group that has been identified previously. This is the first report that deer can be a reservoir of GUD+ STEC O157:H7 in Japan.