David Tennant has just turned 50 years old, and fans of the actor are wishing him the very best on his special day. Very well known for his run as the Tenth Doctor on Doctor Who among many other memorable roles, Tennant's fans stretch all across the world. On social media, thousands of these fans are now banding together to wish Tennant a happy 50th birthday, and this even includes some of his famous friends.

"Happy Birthday to David Tennant, seen here doing outreach work with the underprivileged and derelict. You are doing the Lord's work, David," legendary author Neil Gaiman writes, posting a photo of himself alongside the actor. Tennant played the demon Crowley on Gaiman's Amazon series Good Omens, which is based on the original novel co-written with Terry Pratchett.

"A very, very Happy Birthday to our Demon Crowley #DavidTennant," added Pratchett.

A Crowley fan account tweeted: "Happy 50th birthday to David Tennant! a man of many talents and behind many iconic characters such as our favourite demon, Crowley! Nothing but respect and so much love for this incredible human being."

"to the man who might be 50 but still is 10 years old and literally the most amazing and perfect human being in the universe. happy birthday David Tennant," tweeted another fan of the actor.

Another tweet reads: "Happy birthday David Tennant aka the literal ball of sunshine and the love of my life. you mean the world to me and we are so VERY lucky to be blessed with you."

"HAPPY 50TH BIRTHDAY TO DAVID TENNANT," says someone else. "You are truly a wonderful person and deserve all the goodness in this world. I just wanna say thank you, for being the light of my life, for giving me the meaning to carry on, for everything. Wish you a very happy happy birthday!"

Meanwhile, another fan highlights one of Tennant's more overlooked roles by writing, "Happy 50th birthday David Tennant. Yes, yes, Doctor Who, Broadchurch, blah blah blah. Everyone knows your best role was Sir Piers Pomfrey in St Trinians 2: The Legend of Fritton's Gold."

Of course, Tennant's incarnation of The Doctor is a particular favorite among fans of Doctor Who, and many fans of the sci-fi series are joining the birthday festivities. The actor is also known for playing DI Alec Hardy in the crime drama series Broadchurch, the sinister villain Kilgrave in the Netflix superhero series Jessica Jones, and the voice of Scrooge McDuck in the DuckTales reboot. More recently, Tennant has been playing himself on the British lockdown comedy Staged.

Back in January, it was announced that Tennant will be reprising the role of the Tenth Doctor for a new audio adventure, joining his father-in-law Peter Davison as the Fifth Doctor. Called Doctor Who: Out of Time 2 - The Gates of Hell, the special is set to be released in June via Big Finish. For now, let us join the Doctor Who community and the rest of Tennant's fans by wishing the actor a very happy 50th birthday!