Why Robert Irwin's Sister Bindi Doesn't Call Him By His Real Name

Since his gradual rise to stardom, Robert Irwin has become a household name. The son of "Crocodile Hunter" Steve Irwin has probably heard his moniker shouted plenty of times by fans of "Dancing with the Stars" or viewers of his spicy transformation pics in his Bonds underwear ad. Many even remember him as Bob, which Steve called him as a baby — though he seemingly grew out of it after his father's tragic death. But fans might not know that Robert has a secret nickname: Brian.

According to Robert, his older sister, Bindi Irwin, occasionally referred to him as Brian growing up. "She still calls me Brian," the wildlife conservationist told "Good Morning America" in November 2025. "Especially if I've annoyed her a little bit." The nickname comes from an old video — which Robert posted on Instagram for Bindi's birthday in 2024 — of Bindi meeting her baby brother for the first time in the hospital after he was born. While holding Robert, Bindi said, "I think by the way he is, I'll call him Brian." Her father then gently reminded her, "His name is Robert." Even so, Bindi adorably insisted, "I'll call him Brian for short."

Bindi — who is now married to her longtime beau, Chandler Powell, and has a daughter of her own — explained on the Australian talk show, "The Project", why she gave Robert that random name. "When Robert was born, my job at the Australia Zoo was naming all the animals," she shared. "So, I figured that when my baby brother was born, I would have to name him, too."

The truth about Bindi Irwin's relationship with her little brother, Robert Irwin, is that they are incredibly close. The siblings were only 8 and 2, respectively, when their father, Steve Irwin, died from a tragic stingray attack in 2006. Over the years, Bindi and Robert have supported each other in ways that would melt any parent's heart. In August 2025, Bindi announced that she had uprooted her family in Australia and hauled them to Los Angeles temporarily to cheer on Robert during his season on "Dancing with the Stars" — a show Bindi won in 2015 with her dance partner, Derek Hough. Bindi said in her move announcement on Instagram, "I know in my heart that [Robert] is going to make it far because he is a fantastic human being."

But Robert's biggest fan on and off the ballroom floor is his niece, Bindi's daughter, Grace Irwin, with whom the zookeeper has a sweet relationship. In 2022, Robert told E! Insider that being an uncle to Grace was "so surreal," adding, "It's the best job I've ever had." Ever since Bindi and her husband, Chandler Powell, welcomed Grace in 2021, Robert has reminded his sister of their late father. Bindi told The Australian Women's Weekly that his "uncle energy" resembles Steve in many ways, including his fearlessness to explore. "Dad was such an adventurer and I see that in Robert," Bindi said, adding, "I see he is so similar to Dad, and I'm really glad that Grace is gonna have that energy in her life, like she would've had from Dad."