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We examine the possible role of turbulence in feeding the emission ofgamma-ray bursts (GRBs). Turbulence may develop in a GRB jet as the result ofhydrodynamic or current-driven instabilities. The jet carries dense radiationand the turbulence cascade can be damped by Compton drag, passing kinetic fluidenergy to photons through scattering. We identify two regimes of turbulencedissipation: (1) "Viscous" - the turbulence cascade is Compton damped on ascale $\ell_{\rm damp}$ greater than the photon mean free path $\ell_\star$.Then turbulence energy is passed to photons via bulk Comptonization by smoothshear flows on scale $\ell_\star<\ell_{\rm damp}$. (2) "Collisionless" - thecascade avoids Compton damping and extends to microscopic plasma scales muchsmaller than $\ell_\star$. The collisionless dissipation energizes plasmaparticles, which radiate the received energy; how the dissipated power ispartitioned between particles needs further investigation with kineticsimulations. We show that the dissipation regime switches from viscous tocollisionless during the jet expansion, at a critical value of the jet opticaldepth which depends on the amplitude of turbulence. Turbulent GRB jets areexpected to emit nonthermal photospheric radiation. Our analysis also suggestsrevisions of turbulent Comptonization in black hole accretion disks discussedin previous works.

Sub-photospheric turbulence as a heating mechanism in gamma-ray bursts