Toxoplasma gondii is an important zoonotic parasite causing significant health problems to humans and animals. In recent years, a number of investigations about the seroprevalence of T. gondii in China have been reported, but little is known on the prevalence of toxoplasmosis in sheep in northern China. In the present study, a total of 288 sheep serum samples were collected from Inner Mongolia, Heilongjiang, Jilin and Hebei provinces of northern China for T. gondii antibody survey using a latex agglutination test (LAT). Of these, 87 (30.2%) serum samples were positive for antibodies to T. gondii, and the antibody titres ranged from 1:64 to 1:1,024. Seroprevalence of T. gondii infection in sheep was 17.1% in Inner Mongolia, 33.8% in Heilongjiang, 24.6% in Jilin and 46.3% in Hebei. Age and rearing system significantly affected seropositivity. The present survey indicates antibodies to T. gondii are widely prevalent in sheep in northern China, which may cause public health problems in these provinces.