The 20-year-old Australian conservationist and television personality paid tribute to the former Crocodile Hunter star with a family photo on Instagram.
The throwback picture shows Bindi with Steve, mom Terri Irwin and brother Robert Irwin. Steve died at age 44 in September 2006 after being pierced with a stingray barb.
"Together forever," Bindi captioned the post, adding a heart emoji.
Bindi also honored Steve Saturday on Australian Father's Day. She posted a throwback video of her dad marveling over her lion costume.
"'The Lion King,'" the star wrote. "Happy Australian Father's Day. I'm thankful every day that these moments were captured on camera."
Terri paid tribute to her late husband on Twitter.
"Happy Father's Day Australia," she wrote. "More than anything, Steve loved being a dad. He'd be so proud of his kids. Sending love to all the dads today."
Steve was honored with a posthumous Hollywood Walk of Fame star in April. Bindi, Terri and Robert attended the ceremony in Los Angeles, where they discussed Steve's memory with reporters.
"It's been over 10 years now, and the grief is always going to be there, but I think now, it's moving forward and remembering everything dad worked so hard for," Bindi told Entertainment Tonight.