This study was undertaken to determine the presence of aflatoxin M1 (AFM1) in animal milk. In addition, exposure of infants to aflatoxin M1 (AFM1) and lactating mothers to aflatoxin B1 (AFB1) was examined using AFM1 in breast milk as a biomarker for exposure to AFB1. In total, 100 samples of fresh animal milk and fermented milk (buttermilk) and 80 samples of human breast milk were collected during the period 2011–2012. An enzyme-linked immunosorbent assay (ELISA) was used for the analysis of milk samples. AFM1 was detected in all animal fresh and fermented milk samples. The concentrations of AFM1 in 70 samples of fresh and fermented milk were higher than the maximum tolerance limit accepted by the European Union and the United States of 50 ng/kg. In human milk samples the average concentration of AFM1 was higher than the maximum tolerance limit accepted by the European Union and the United States of 25 ng/kg. Logistic regression analysis failed to show a correlation between AFM1 and type and amount of dairy consumption, vegetables, fruits, and meat. However, an association between AFM1 and cereal consumption was detected. This study is the first to report on the occurrence of AFM1 in milk consumed by the Jordanian population.