Tennant's portrayal of the Tenth Doctor is of an outwardly charismatic and charming adventurer whose likable and easygoing attitude can quickly turn to righteous fury when provoked.

This incarnation's companions include some who travelled with his previous incarnation: working-class shop assistant Rose Tyler (Billie Piper), her boyfriend Mickey Smith (Noel Clarke), and former "Time Agent" Captain Jack Harkness (John Barrowman), as well as medical student Martha Jones (Freema Agyeman) and fiery temp worker Donna Noble (Catherine Tate).

[24] He generally wears either a dark brown (with blue pinstripes) or a blue (with rust red pinstripes) four-buttoned suit with a shirt and a tie, or a shirt and t-shirt, a light brown faux-suede duster coat (which he claims was given to him by Janis Joplin), and different coloured pairs of Converse All-Star trainers, depending on his suit.

After eventually waking up, he defeats the alien Sycorax and saves Earth; in the process, he loses a hand, which regrows owing to his recent regeneration.

Amongst other second-series (2006) adventures, the Doctor and Rose save Queen Victoria (Pauline Collins) from a werewolf in "Tooth and Claw", resulting in the creation of the anti-alien Torchwood Institute.

After saving parallel Earth, Mickey decides to stay and help stop the Cybermen around the world despite The Doctor telling him he can never return in "The Age of Steel".

The series finale takes place in contemporary London, where modern-day Torchwood is the scene for war between the evil alien Daleks and parallel-universe cyborgs the Cybermen; saving the Earth costs the Doctor Rose, who is stranded in a parallel universe, along with Mickey and her mother, in "Doomsday".

In the closing scene of "Doomsday", a mysterious bride called Donna Noble (Catherine Tate) inexplicably appears in his TARDIS.

Following this adventure, in the dénouement of series finale "Last of the Time Lords", Jack and Martha both depart the TARDIS, and The Doctor is shocked to see what appears to be the RMS Titanic crash into it.

In the premiere episode of the fourth series (2008), "Partners in Crime", The Doctor is reunited with Donna Noble, Wilfred's granddaughter, who becomes his regular companion.

He meets archaeologist and future companion River Song (Alex Kingston) for the first time from his perspective in the two-parter, "Silence in the Library" and "Forest of the Dead"; she dies, but he stores her consciousness to a hard drive to live on forever, after accepting that one day she will come to mean a lot to him.

The Doctor was fatally wounded during the event, causing him to regenerate, although he chooses to maintain his current self while transferring residual energy into his previously severed hand.

In lieu of a 2009 series, Tennant appears as the Tenth Doctor, without a regular companion, in several special episodes over the course of 2008 and 2009, the last of which aired on New Year's Day, 2010.

In "The Waters of Mars", The Doctor tries to alter history and avert the death of one-off companion Adelaide Brooke (Lindsay Duncan); when she commits suicide, he begins to feel his mortality weigh down upon him.

[a] He gives Donna a winning lottery ticket on her wedding day, buying it with money he borrowed from her late father in the past, saves Martha and Mickey from a Sontaran sniper, saves Sarah Jane's son Luke (Tommy Knight) from a car, introduces Jack to a romantic interest (Russell Tovey), and finally, just before regenerating into the Eleventh Doctor (Matt Smith), informs Rose in 2005 that she is about to have a "great year".

In an appearance on The Friday Night Project in 2007, Tennant plays a female companion to the Tenth Doctor (Justin Lee Collins) on the Pink Planet, where they are confronted by the alien Gay Lord (Alan Carr).

In the final episode of Extras (December 2007), a brief scene shows The Doctor and an unidentified Wren companion attacked by Schlong, a slug-like alien played by Andy Millman (Ricky Gervais).

The Tenth Doctor is also featured in political satire; in a 2007 episode of Dead Ringers, when faced by the question of Gordon Brown's succession, Tony Blair (impressionist Jon Culshaw) regenerates into David Tennant after promising "New Labour is all about renewal", later vowing 100 more years of power.

Arriving in 2003, the Doctor hints to Sparky the Wonder Penguin (the strip's main character) that in five years' time, the next President could be a black man, with the middle name Hussein, whose father was a Muslim.

On 26 October 2015, it was announced Tennant would reprise his role for The Tenth Doctor Adventures, a series of full-cast audio stories produced by Big Finish Productions.

The first volume of stories had the reprise of Catherine Tate as Donna Noble, consisting of Technophobia, Time Reaver, and Death and the Queen, which were released in May 2016.

The stories consisted of Infamy of the Zaross (with Camille Coduri as Jackie Tyler), Sword of the Chevalier, and Cold Vengeance, which were released in November 2017.

He made brief cameos at the end of the Jenny – The Doctor's Daughter series and the final story of Big Finish's multi-Doctor anniversary special The Legacy of Time.

As part of the multi-platform Time Lord Victorious storyline, Tennant co-starred in Echoes of Extinction alongside Paul McGann as the Eighth Doctor.

He was set to be the first Doctor to appear in the spin-off series Torchwood, reuniting Tennant with John Barrowman as Captain Jack Harkness and Gareth David-Lloyd as Ianto Jones, for Absent Friends.

In September 2022, Big Finish released the Tenth Doctor, Classic Companions special, which reunites the Doctor with K9, Ace, Leela and Nyssa; he retrieves K9 from a temporal anomaly, helps an alternate version of Leela save a village, rescues Nyssa from a criminal using Time Lord technology as part of a scam, and subsequently leaves K9 with Ace after they stop Axos ("The Claws of Axos") from escaping its time loop prison.

Camille Coduri reprised her role as Jackie Tyler to narrate a pair of stories featuring the Tenth Doctor's meta-crisis clone in The Siege of Big Ben and Flight into Hull set on the parallel Earth.

The Tenth Doctor appears alongside his fellow incarnations as a playable character in the 2015 toys-to-life crossover game LEGO Dimensions.

[39] He, as well as the Thirteenth Doctor, appears as a playable character that users could purchase for free from the Avatar Shop within Roblox for a limited time, which also featured the Pting as a shoulder accessory, and the TARDIS in the form of a backpack.

[40] Tennant's tenure as the Tenth Doctor is highly regarded among fans of the show and his character received critical acclaim for his complexity and humanity.