<p>Oncolytic adenovirus has been widely evaluated as a cancer treatment agent with tolerable toxicity profile. We have recently developed a new oncolytic adenovirus Adf35(OGN) with two immunostimulatory transgenes alpha-1,3-galactosyltransferase (<i>GGTA1</i>) from <i>Sus scrofa</i> and neutrophil-activating protein (NAP) from <i>Helicobacter pylori</i>. Adf35(OGN) can kill tumor cells and trigger a strong immune response against tumor antigens. Here, we report the toxicity and biodistribution of Adf35(OGN) in Syrian hamster and GGTA1-knockout mouse. The virus was delivered subcutaneously in naïve hamsters and intratumorally in <i>GGTA1-</i>knockout mouse in multiple doses at dosages of 1–5 × 10¹¹ viral particles (VP)/kg. The virus did not replicate in any tissues, evidenced as low or no viral copies detected by qPCR. The virus was also found at low levels in biofluids (saliva, urine, and feces), indicating that spread to the environment is low with a low risk of secondary infections via shedding. The virus did not cause any biochemical, hematological, or histopathological alterations. In summary, Adf35(OGN) has a good safety profile in these animal models and these results support future clinical evaluation for Adf35(OGN).</p>