Mark Speer (born November 9, 1979) is an American musician and songwriter, best known as the guitarist and one of the founding members of the musical trio Khruangbin.

[2] Speer met future bandmate Donald "DJ" Johnson in 2004 while playing in Rudy Rasmus' St. John's Methodist Church gospel band in Houston, Texas.

He later met Laura Lee Ochoa through mutual friends, where they initially connected over a shared love of Afghan music and Middle Eastern architecture.

Speer has recorded five studio albums with Khruangbin: The Universe Smiles Upon You (2015), Con Todo el Mundo (2018), Mordechai (2020), Ali (with Vieux Farka Touré; 2022), and A La Sala (2024).

[2] Much of Speer's guitar style comes from seeking to emulate the harmonic and timbral characteristics of other instruments, such as the krar, bağlama, rubab, shamisen, mbira, and djembe.

[8] Speer has mentioned Roy Ayers, Prince, Roots Radics, Mark Knopfler, Steely Dan, Lata Mangeshkar, Sezen Aksu, DJ Sun, and Ernie Isley as his biggest influences.