Dylan Efron has penned a sweet message to US Dancing With the Stars winner, Robert Irwin.

Following the grand finale of the US show, the TV star and brother of actor Zac Efron made sure to congratulate the wildlife conservationist.

"Congrats," Dylan wrote in an Instagram post alongside a series of pics of him and Robert smiling aboard a private jet.

"This experience was made better with you alongside, can't wait to hang out in the wild."

The Crikey! It's the Irwins star reciprocated the love, writing in the comments, "Dude, you are the best. I'm so happy I got to be on this season with you. Catch you soon, mate."

Irwin and his dance partner, Witney Carson, took home the Len Goodman Mirrorball Trophy for Dancing With the Stars season 34.

Efron and his partner, Daniella Karagach, placed fourth in the competition, while social media personality Alix Earle and Val Chmerkovskiy were named runners-up.

Efron had the support of his longtime girlfriend at the finale. His childhood sweetheart, Courtney King, was spotted at his trailer before the show on Tuesday afternoon.

"We're from the same town," he told The Viall Files in March.

"It works out really well. It's not, like, I'm hiding her from the world or anything. She understands the job, all the stuff. She doesn't really like being on camera.

"It's cool because she's actually not on social media and she works a 40-hour week job," he added.