Kevin Malone is an accountant at the fictitious paper distributor Dunder-Mifflin. Kevin is bald, overweight, and seems to have just two facial expressions: a scowl and an impish grin. He speaks in a slow, monotone voice, rarely expressing any emotion, although he is often prone to giggle at things that would typically amuse a child. Much of Kevin's humor derives from the incongruity between his deadpan personality and his juvenile sense of humor. Kevin is typically quite subdued with his hangdog face, although he is known for making blunt or offensive comments regarding the other employees. He hints toward unbecoming Internet habits, most likely pornography, as alluded to in the episodes "E-mail Surveillance" and "Take Your Daughter to Work Day". He is very concerned about the e-mail surveillance uncovering the contents of his hard drive and actually flees an interview with the cameras in order to ensure that his stepdaughter had not found the same content.

Kevin is engaged to a woman named Stacy, who has a daughter named Abby. Stacy is the fourth woman to whom Kevin proposed, but the first to say yes, and he is happy, though he secretly considers her a second choice to one of the other women, Melissa Riley. Kevin plays drums and is also the lead singer in a local tribute band. The group initially was a Steve Miller Band tribute called "Jokers and Tokers", but recently refocused on the music of The Police, and rebranded accordingly as "Scrantonicity," a homage to their album Synchronicity. Kevin is a fan of the Detroit Pistons, his favorite foods are Cup noodles and M&M's, and his favorite movie is American Pie 2, he also likes Weekend at Bernie's. He is not given much responsibility by his supervisor, Angela Martin, although he enjoys the privilege allowed him of shredding company documents, in no small part because he simply enjoys shredding things. In "Health Care," it was hinted that he suffers from anal fissures. In "Casino Night," he reveals that he won a World Series of Poker bracelet in 2002, but he nonetheless suffers defeat at the hands of an unwitting Phyllis.

Kevin suffers from plantar hyperhidrosis ("Grief Counseling" deleted scene). Angela is regularly disgusted by Kevin's feet.

Kevin is the only minor character in The Office to be directly based on a character from the British original version. He is based on Keith Bishop, who shares Kevin's lack of communication skills, and became particularly popular after an episode where boss David Brent conducts a staff appraisal, to which Keith stoically fails to respond to questions. Keith shares Kevin's musical interest (as a disc jockey, not a musician), but not Kevin's childish sense of humour.