He began his career in the early 2010s with minor guest roles on Brooklyn Nine-Nine, Friends of the People, Guy Code, and Wild 'n Out before being hired as cast member on the NBC late-night sketch comedy series Saturday Night Live which he starred in for eight seasons from 2014 to 2022.

He told The New York Times that it was "overwhelming" and that he later acted out in school as a result of the trauma, at one point ripping his hair out until he was bald.

[5] In October 2016, he revealed on The Breakfast Club morning radio show that he struggled with suicidal thoughts when he was younger and that the music of Kid Cudi saved his life.

His debut garnered positive critical notice,[21][22] with his most noted skits during the season including an Indiana Jones-style sketch in which he and Dwayne "The Rock" Johnson, after being pelted with poison darts, were forced to mutually suck poison out of each other's various body parts,[14][23] an endeavor that eventually found them entangled in the "69" position.

[14] Over the years, Davidson played a number of characters, the most famous being Chad, an easily distracted apathetic man who first appeared in the season 41 episode hosted by Julia Louis-Dreyfus, as a pool boy who becomes entangled with a lonely housewife.

[25] Among his bolder jokes was one at the expenses of fellow roaster Snoop Dogg, host Kevin Hart, and their 2004 film Soul Plane.

Davidson, whose firefighter father died responding to the September 11 attacks, called the film "the worst experience of [his] life involving a plane".

Mulaney and Davidson became close after appearing together on The Tonight Show Starring Jimmy Fallon and Saturday Night Live.

[36] The series debuted to mixed reviews with The Guardian describing it as "messy" and compared it unfavorably to other shows, writing, "Though every piece seems to come from somewhere else, a derivative streak that undercuts the touches of personal specificity.

[44] He is close friends with Seattle Mariners pitcher Matthew Festa; the two were classmates at St. Joseph by the Sea High School.

[47] Davidson was diagnosed with Crohn's disease at age 17 or 18, for which he receives intravenous biologic therapy, and has used medical marijuana for pain management and recreationally.

[6] During an interview on comedian Marc Maron's podcast, Davidson clarified that the only drug he used was marijuana and, while he has since cut back on its use considerably, the personal and emotional problems he initially assumed were the result of his daily marijuana use were actually caused by his newly diagnosed borderline personality disorder, for which he has since been undergoing treatment.

[49][50] On December 3, 2018, Davidson shared a candid Instagram post in which he expressed thoughts of suicide, before deleting his account on the social media platform entirely.

[51] The New York Police Department conducted a wellness check on Davidson in response to social media posts from followers and former fiancée Ariana Grande.

[52][53] Davidson had been at the Saturday Night Live studio at the time preparing for the last episode of the year before its holiday hiatus.

Davidson and John Mulaney, comedian and former SNL writer, made humorous references to the Instagram post during the Weekend Update segment of the first episode following the holiday hiatus on January 19, 2019.

[64] In January 2019, Davidson was reported to be in a relationship with actress Kate Beckinsale, twenty years his senior, but by April they had "called time on their romance".

[70] During her time hosting an episode of SNL, the two shared an on-screen kiss in a Disney-themed sketch, where they played Jasmine and Aladdin.

[70] The music video for Eazy depicted a claymation figure of Davidson being kidnapped, buried, and showed his severed head.

"[78] In March 2022, spaceflight company Blue Origin announced that Davidson would be an "honorary guest" alongside five paying customers onboard NS-20, a suborbital flight of its New Shepard craft planned for later that month.

"[84] In a statement posted on its website, the diocese criticized the "disgraceful and offensive skit" and added, "The faithful of our Church are disgusted by the harassment by those in news and entertainment, and this sketch offends millions.

"[85] Davidson's comments came after the Diocese of Brooklyn and Queens agreed to a record $27.5 million settlement for sex abuse allegations in September 2018.

[86] Davidson was criticized for mocking Republican congressional candidate Dan Crenshaw, who wears an eye patch as a result of a wound incurred while serving in Afghanistan.

"[88][89][90][91][92] In response to backlash over the comments, Davidson apologized and appeared beside Crenshaw the following Saturday on an SNL Weekend Update segment.