Alex Danvers

Alex Danvers
Arrowverse character
Chyler Leigh as Alex Danvers in a promotional image for season one.
First appearance	"Pilot" Supergirl October 26, 2015
Last appearance	"Armageddon, Part 4" The Flash December 7, 2021
Created by	Greg Berlanti Ali Adler Andrew Kreisberg
Portrayed by	Chyler Leigh Jordan Mazarati (young; 2003) Olivia Nikkanen (young; 2007 and 2009)
In-universe information
Full name	Alexandra Danvers
Alias	Sentinel
Title	Ph.D. M.D.
Occupation	Bio-engineer, physician, scientist, field agent, director of the DEO
Family	Eliza Danvers (mother) Jeremiah Danvers (father, deceased) Kara Danvers (adoptive sister)
Significant others	Kelly Olsen (wife)
Children	Esme (adoptive daughter)
Abilities	Scientist, physician, tactician, and detective Expert in human and extraterrestrial physiology Master hand-to-hand combatant, martial artist, and markswoman Proficiency with advanced DEO and extraterrestrial weaponry Utilizes Kryptonite powered exosuit and sword

Alexandra "Alex" Danvers Ph.D. M.D., also known as Sentinel, is a fictional character from the Arrowverse television series Supergirl, portrayed by actress Chyler Leigh. Created by executive producers Greg Berlanti, Ali Adler, and Andrew Kreisberg, the character was introduced in the pilot episode as the elder adoptive sister of protagonist Kara Danvers / Supergirl. Alex is a bioengineer, physician, scientist and a field agent of the DEO, a secret government agency that works to protect the Earth from extraterrestrial threats. She later becomes the director of the organization at the end of season three, after having been J'onn's second-in-command for years, and remains so through season five. Alex is also featured in the show's digital tie-in comic book series, Adventures of Supergirl, as well as the 2017 four-part Arrowverse crossover event "Crisis on Earth-X", with Leigh reprising her role across The Flash, Arrow, and Legends of Tomorrow.