The first season of the American mystery comedy-drama television series Only Murders in the Building, often abbreviated as OMITB, premiered on August 31, 2021, on Hulu.

It also received the Seal of Authentic Representation from the Ruderman Family Foundation and The ReFrame Stamp for hiring people of underrepresented gender identities, and of color.

Charles-Haden Savage, a misanthropic former television actor who starred in the 1990s crime drama Brazzos; Oliver Putnam, a struggling Broadway director; and Mabel Mora, a young apartment renovator, live at the Arconia.

They find more and more evidence, such as Tim's frantic phone call in the elevator and a package addressed to him that contained an engagement ring.

Meanwhile, Oliver struggles with his relationship with his son, Charles discusses his need for solitude, and Mabel expresses her fear of getting personal with people.

[3][4] In November 2020, Aaron Dominguez joined the cast in a series regular role, confirmed to be playing the character of Oscar.

[5][6] In addition to the main cast, the season also features multiple guest stars, such as Tina Fey, Jackie Hoffman and Da'Vine Joy Randolph.

[16] On September 3, 2021, it was reported that the first season of Only Murders in the Building set a record for the most-watched comedy premiere in Hulu's history.

The website's critics consensus reads, "Only Murders in the Building's silly approach to true crime obsessives is at once hilarious and insightful, thanks in large part to its extremely charming central trio.

[22] Kristen Baldwin of Entertainment Weekly gave the season a "B" grade and wrote, "Only Murders delivers above-average laughs, a clever mystery, and a starry cast.

"[23] Reviewing for Rolling Stone, Alan Sepinwall gave a rating of four and a half out of five stars for the season, and said "The series soon turns out to be—like The Princess Bride, Galaxy Quest, or Jane the Virgin—that rare and wonderful thing: the parody that also offers a great example of the genuine article.

"[24] The first season received 17 nominations at the 74th Primetime Emmy Awards, with three wins, including Nathan Lane for Outstanding Guest Actor in a Comedy Series.

[25][26] "The Boy from 6B", the seventh episode of the season, was given the Seal of Authentic Representation from the Ruderman Family Foundation for the portrayal of Theo by James Caverly, as an actor with a disability and at least five lines of dialogue.