Michael Robert Henrion Posner (/ˈpoʊznər/ POHZ-nər; born February 12, 1988) is an American singer, rapper, songwriter, poet, and record producer from Detroit. He signed with J Records in 2009 and released his debut single "Cooler Than Me" the following year. The song peaked at number six on the Billboard Hot 100 and received septuple platinum certification by the Recording Industry Association of America (RIAA). His follow-up single, "Please Don't Go" peaked within the top 20 of the chart and received triple platinum certification; both songs preceded the release of his debut album, 31 Minutes to Takeoff (2010), which peaked at number 12 on the Billboard 200 and received mixed critical reception. In 2014, Posner parted ways with J Records in favor of Island Records.

In 2015, an EDM remix of Posner's song "I Took a Pill in Ibiza" peaked within the top ten on the charts in 27 countries, and the top five of the Billboard Hot 100. Its success led to the release of his second studio album, At Night, Alone (2016), which peaked at number eight on the Billboard 200 and was met with positive critical reception. His third album, A Real Good Kid was released in 2019. His fourth album Operation: Wake Up (2020), was met with continued praise despite failing to chart.

Along with his recording career, he has served as a record producer and songwriter for acts including Justin Bieber, Big Sean, Maroon 5, Iggy Azalea, Big Time Rush, Austin Mahone, Nick Jonas, Cher Lloyd, and Labrinth; he co-wrote "Boyfriend" by Justin Bieber and "Sugar" by Maroon 5, among others. In 2017, Posner released his first book of poetry, Tear Drops & Balloons. He is also one-half of alternative hip-hop duo Mansionz, completed by Florida rapper blackbear.

Michael Robert Henrion Posner was born on February 12, 1988, in Detroit. He grew up in Southfield, a northern suburb of Detroit. He has a sister who is six years older. His father was a Jewish criminal defense lawyer and his mother is Catholic. Posner attended Bingham Farms Elementary School, Berkshire Middle School, and graduated from Groves High School where he ran varsity track and cross-country. He attended Duke University, where he was a member of the Sigma Nu fraternity. He graduated with a B.A. degree in sociology with a 3.6 GPA.

Posner's father, Jon, died on January 11, 2017; his mother is Roberta Henrion; and his sister, Emily Henrion Posner, is a civil rights attorney.

Posner started out as a record producer, working on some tracks with his hometown friend Big Sean. Posner's second mixtape, A Matter of Time (his first mixtape was Reflections of a Lost Teen) started attracting industry attention in 2009. Working with Don Cannon and DJ Benzi, the mixtape was recorded at Duke University in March 2009 under the name "Mike Posner & the Brain Trust", the Brain Trust referring to Posner's supporters. The release was unusual for being distributed for free through iTunes U, a channel designed for educational audio content. Although Posner was not the only artist to take advantage of this loophole, his release was the most organized and high profile, and attracted the largest response, immediately reaching the number one position on the iTunes U chart. Posner signed a record deal with J Records (RCA/Sony) in July 2009, after his junior year at Duke University. He chose to return to Duke after signing and toured on the weekends while at the same time recording for his debut album.

Posner's third mixtape One Foot Out the Door was released in October 2009. The mixtape was accompanied by a web series of the same name which aired bi-weekly from September to December. His debut album, 31 Minutes to Takeoff was released in August 2010. The first single, "Cooler Than Me" peaked at number 6 on the US Billboard Hot 100. He performed at Bonnaroo, a music festival, and on the 2010s Warped Tour. The second and third singles, "Please Don't Go" and "Bow Chicka Wow Wow" reached the top 20 and 30 on the Hot 100 respectively. The latter was released with an added verse by rapper Lil Wayne. Posner won a 2011's ASCAP Award from the publishing organization for "Cooler Than Me". On October 7, 2011, RCA Music Group announced that it was disbanding J Records along with Arista Records and Jive Records. With the shutdown, Posner (and all other artists previously signed to the three labels) will release his future material on the RCA Records brand.

After the release of his debut album, Posner began working on his second studio album under the title Sky High and released the single "Looks Like Sex" to digital outlets on December 2, 2011. As a prelude to the release of the album, he released a third mixtape, The Layover. However, with the success of his first album, he began to feel uncomfortable with being in the spotlight and struggled with depression. He took a break from making music to write and produce songs for other artists. He later announced via Twitter that his next upcoming album would be titled Pages and would be released in early June or late in the summer of 2013. His single "The Way It Used To Be" premiered on digital outlets on June 11, 2013. In September 2013, it was announced that he had filmed a music video for his new single "Top of the World" which would appear on his upcoming Page 1 EP, set for release in October. The song was originally used for a Reebok campaign, and made available as a free download under the title "Tapada World" as a special remix. The song was released on December 17, 2013, featuring Big Sean; the music video came out on December 19.