It's Dr Ranj's 40th birthday!
You might remember seeing the jiving doctor on CBeebies or perhaps on the latest series of Strictly Come Dancing, during which the nation fell in love with his amazing outfits and enthusiastic dance moves.
To celebrate his big birthday, here are some fun facts that you might not know about him.
Despite being very busy with TV programmes, Dr Ranj works as a paediatrician for the NHS, which means he looks after children who are unwell.
He has been a practicing doctor since 2003 - so for 16 years!
Back when his CBeebies show Get Well Soon launched in 2012, he said: "I've worked in a variety of different hospitals in lots of specialties. I look after everyone from extremely premature babies to young adults with complex disabilities. It's busy but I love every minute!"
Dr Ranj's skills go beyond being a doctor and a popular TV presenter.
He has also published two children's books.
One is called Skelebones, which explains how our skeleton works, and the other is called Food Fuel, which follows the process of eating food and how it gets digested.
"Get Well Soon is a unique pre-school show based on children's experiences of going to the doctor," he said. "Its aim is to educate as well as entertain, and allow kids to learn about their bodies in health and sickness."
His vocal talents went beyond CBeebies though, as he also sings in a show choir called the Adam Street Singers.
Dr Ranj's enthusiastic energy was the perfect match for the Saturday night TV show Strictly Come Dancing.
He was partnered up with Janette and the two lasted until week seven with a monster mash jive and a doctor's surgery cha cha.
After the couple were eliminated from the competition, Janette said: "He is an incredible human being for what he does as an actual job.
"On this show you get to celebrate people that have never done something like this before, and for me Ranj is the epitome of what Strictly Come Dancing is about."
Dr Ranj celebrated his birthday with an amazing party at the weekend.
He was joined by Strictly pal Janette and the pair even performed a special dance for everyone.
She described his party as being "a room filled with so much love for this amazing man!"
After the party, he sent a message to his loved ones on social media, saying: "The biggest thank you to ALL my friends & family who celebrated with me this weekend, especially the gorgeous @JManrara! ❤️"
Happy birthday from everyone at Newsround, Dr Ranj!