Models of cosmic inflation generically predict a weak but potentially detectable amount of primordial non-Gaussianity (PNG), which can be used to obtain insights into the degrees of freedom during inflation and their interactions. The simplest types of PNG are the local and nonlocal (equilateral and orthogonal) shapes of the primordial three-point correlators, which are predicted by models with multiple light fields and derivative interactions in single-field inflation, respectively. In this paper, we place constraints on local, equilateral, and orthogonal non-Gaussianities using the power spectrum and bispectrum extracted from the first public release of the Dark Energy Spectroscopic Instrument (DESI). Our analysis makes use of higher-order clustering information through a consistent effective field theory (EFT) model for both the power spectrum and bispectrum at one-loop order. Using robust scale cuts where the EFT description is valid, we find the following constraints on PNG amplitudes: $f_{\mathrm{NL}}^{\mathrm{loc}}=-0.1\pm 7.4$, $f_{\mathrm{NL}}^{\text{equil}}=719\pm 390$, $f_{\mathrm{NL}}^{\mathrm{orth}}=-200\pm 100$ (at 68% confidence level). Nonlocal PNG constraints can be further improved by combining high-redshift DESI with legacy BOSS data and using simulation-based priors on bias parameters, yielding the strongest large-scale structure constraints to date $f_{\mathrm{NL}}^{\text{equil}}=200\pm 230$, $f_{\mathrm{NL}}^{\mathrm{orth}}=-24\pm 86$. Our constraint on $f_{\mathrm{NL}}^{\mathrm{loc}}$ is competitive with the cosmic microwave background (CMB) limit; the combination gives $f_{\mathrm{NL}}^{\mathrm{loc}}=-0.0\pm 4.1$, 18% stronger than the CMB-only result, which represents the strongest bound on multifield inflation yet obtained.

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• Inflation
• Large scale structure of the Universe