Esa Onttonen (born 1975 in Jyväskylä) is a guitarist, composer, and arranger whose main bands are Esa Onttonen Labra and Gourmet, which he founded in 1997 with saxophonist Mikko Innanen.

Onttonen has performed extensively in Europe with Gourmet and the improvising trio collective Gnomus, and has released a total of ten albums with these bands. In addition, Onttonen has composed and arranged music for various ensembles, from brass sextets to symphony orchestras, and especially for big bands such as UMO Jazz Orchestra and Jyväskylä Big Band.

The common thread running through Onttonen's musical career has been the search for alternative approaches to guitar playing, composing, and collective music-making. Onttonen holds a Master of Music degree (Sibelius Academy, 2001) and a Master of Arts degree (Aalto University, 2017). He is currently working on his doctoral thesis at the Sibelius Academy of the University of the Arts Helsinki, researching live composition.