"One Mic" is a song by American rapper Nas, released April 16, 2002 on Columbia Records and distributed through Ill Will Records in the United States. It was issued as the third single from his fifth studio album, Stillmatic (2001). The single peaked at number 43 on the Billboard Hot 100, making it Nas's third top-fifty hit on the chart.

Production for "One Mic" was handled by Nas and hip hop producer Chucky Thompson. Talking about the inspiration for the song, Nas stated: "I'm a huge fan of Phil Collins and I just wanted to take the vibe from 'In the Air Tonight'." Steve Juon of RapReviews wrote that the song features a production technique previously implemented by such hip hop artists as Outkast and the Roots, which he described as "a quiet groove that steadily increases in energy and intensity until an increasingly amped Nas lets his lyrical rage boil over like a Final Fantasy fighter smacked ONCE too often." According to Nick Butler, the song's structure "slowly build[s] up from a simple 'In the Air Tonight' sample toward the full production ... like hearing two mini hip-hop versions of 'Stairway to Heaven', before Nas flips the script for the third verse and does the same thing in reverse."

According to Juon, the final verse has a reversal of this formula, in which Nas "goes from amped up to soft-spoken, drawing you even closer into his rap." "One Mic" begins with a slow, deliberate flow and beat. Music critic Brett Berliner wrote "'One Mic' starts out with a slow beat reminiscent of a crappy R&B song. Throughout the song, Nas' lazy flow turns into an angry rant over a fast paced beat, and finally a siren."

The lyrics of "One Mic" discuss Nas's desire for a simple life ("Only if I had one gun, one girl, and one crib/One God to show me how to do things his son did") and obstacles that prevent it ("[if] One ni**ga front, my face on the front page"), and a lifestyle in which Nas proclaims "All I need is one mic - fuck the cars, the jewelry". It has been noted by music writers for its political consciousness and dystopian themes. Keith Harris of City Pages described the lyrical structure of "One Mic" as "urban claustrophobia distilled and digitized, with Nas's reportorial eye zooming in on a detail, then pulling back to a panoramic overview." Music critic Cynthia Fuchs described the song's lyrical scheme as "building slowly to a crescendo of declaration and rage, then coming back, to seek a way to make a difference, with that precious one mic."

In an interview for Rolling Stone, Nas discussed the theme of the song, stating "'One Mic' is just about the power. It's almost like Hip Hop is Dead in its infant stages, saying how much this is a blessing to be out here, speaking about what's happening in my neighborhood, having the whole world understand and relate." He also referred to commentator Bill O'Reilly's criticism of "Shoot 'Em Up", a song from Nas's fourth album Nastradamus (1999), as he stated "If I didn't have a microphone, I could never talk about 'Shoot 'Em Up', and I was talking about Queens, New York, being shot up. What do I have to do to get somebody to turn around and hear what I'm saying and take it serious? I'm not here just to be in your face talking nonsense, we're talking about reality. For him to be upset or people like him to be upset is insane to me. It just shows how ignorant people are." In the interview, Nas continued to discuss his inspiration and the song's lyrical theme, stating:

'One Mic' just gives me the ability, no matter how much ignorant people are mad that I'm exposing or talking about our country, no matter what the language is, I'm talking in a language that the people can hear, I'm not sugar-coating it. So if it scares people and people feel guilty, people feel like they've got to make up excuses to why the world's this way, no matter what they say, like they've got their mic, I've got mine, and that's what that song's about.

In the song, Nas also asks God to forgive him for his sins. In the hip hop book Beats, Rhymes & Life (2007), music writer Ytasha Womack compared Nas's lyrics on "One Mic" to the work of rapper Tupac Shakur, analyzing it as a song with strong religious, Christian overtones and lyrical themes. Womack wrote that "Nas's references ultimately humanized Jesus, with attempts to show direct parallels between our quest and that of the Wayshower." Womack concluded with analyzing the incorporation of religious themes by Nas in his composition, stating "Nas clung to spiritual questioning, expressing a desire to be like the early mystics, in order to possess their knowledge and powers. While he expresses that he has the potential of the greats, in 'One Mic' he asks God to show him how to do things his son did. Nas intertwined his day–to–day life and decisions with the pressures felt by Jesus and others, doing so almost as a means to somehow transfer their spiritual gifts to himself."

When "One Mic" was released as a single, it entered the Billboard Hot 100 at number 79 on April 20, 2002, ultimately peaking at number 43. On June 8, it debuted on the Hot Rap Tracks chart at number 9, before eventually reaching number 7. The single also peaked on the Hot Rap Singles at number 23, the Rhythmic Top 40 at number 32, and the Hot R&B/Hip-Hop Singles & Tracks at number 14. A remix of "One Mic", featuring a sample of Mtume's "Juicy Fruit" (1983), was later released on the remix album From Illmatic to Stillmatic: The Remixes (2002).