Robert Eric Irwin was born in Essendon, a suburb of Melbourne, Victoria. This marked the beginning of a life deeply intertwined with the Australian landscape and its wildlife.

Growing up, Bob developed a strong fascination with animals, particularly reptiles. He spent much of his time exploring the Australian bush, observing and learning about native fauna. Details of his early education are limited, but his practical knowledge of the natural world was evident from a young age.

During his formative years Bob actively pursued his interest in reptiles, learning how to handle them safely, and studying their behaviours. His knowledge and skills in herpetology continued to grow, which prepared him for a life dedicated to working with reptiles and apex predators.