Thea Dearden Queen, also known as Speedy, is a fictional character portrayed by Willa Holland on The CW television series Arrow, created by Greg Berlanti, Marc Guggenheim, and Andrew Kreisberg.

Although an original creation to the series, she adopts elements from the DC Comics superhero Mia Dearden / Speedy, created by writer Kevin Smith and artist Phil Hester.

Thea is introduced as a senior in high school who is grateful to have her big brother back, but his disappointment in her lifestyle and the secrets he keeps from her about his five years away cause her to slip even further into drug use.

On her 18th birthday, she is involved in a car crash while on the narcotic Vertigo and is subsequently arrested and sentenced to community service for 500 hours at CNRI (City Necessary Resources Initiative) under the supervision of Laurel Lance.

[11] After discovering that Roy worked with the Arrow, Thea, betrayed once again, decides to go with her father and leaves Starling City and her family behind, with no intentions of coming back.

Thea is told that her father used her as a pawn against both Oliver and Ra's al Ghul by drugging and manipulating her into killing Sara Lance, she arranges for him to be captured by the League in retaliation.

It is also revealed that Thea's Lazarus Pit side effect is able to counterattack Damien Darhk's life force drain in addition relieving her bloodlust temporarily.

With Tatsu Yamashiro's help, Nyssa al Ghul gives Oliver the 'Lotus', an elixir used by the Crescent Order that permanently reverses the effects of the Lazarus Pit, saving her life.

[15] She hires Quentin Lance, who had been fired from the SCPD after revealing that he had previously collaborated with Damien Darhk, as the city's deputy mayor, having some daughter-father figure relationship and helping him to beat his alcoholism.

[17] After Oliver's near-impeachment, Thea decides to resign as his chief of staff, fearing that she was relying too heavily on dirty politics, including tarnishing reporter Susan Williams' reputation and considering blackmailing a city council member for his vote.

[23] In the episode "The Thanatos Guild", Thea decides to leave Team Arrow to travel the world to destroy Ra's al Ghul's remaining Lazarus Pits alongside Nyssa and Roy.

[25] When Oliver heads to Nanda Parbat to gain more information on the Monitor from Talia al Ghul, he reunites with Thea and fills her in on his impending death.

[26] Following the events of the crisis, which saw Oliver sacrifice himself to stop the Anti-Monitor, a new reality is formed in which Thea accepts Roy's marriage proposal and Moira was not killed.

[29] In February 2012, it was announced that Willa Holland was joining Arrow as Oliver Queen's "bratty younger sister Thea",[30] beating Melissa Benoist for the part.