  We present the possibility that the seesaw mechanism and nonthermal
leptogenesis can be {investigated} via primordial non-Gaussianities in the
context of a majoron curvaton model. Originating as a massless Nambu-Goldstone
boson from the spontaneous breaking of the global baryon ($B$) minus lepton
($L$) number symmetry at a scale $v_{B-L}$, majoron becomes massive when it
couples to a new confining sector through anomaly. Acting as a curvaton,
majoron produces the observed red-tilted curvature power spectrum without
relying on any inflaton contribution, and its decay in the post-inflationary
era gives rise to a nonthermal population of right-handed neutrinos that
participate in leptogenesis. A distinctive feature of the mechanism is the
generation of observable non-Gaussianity, {in the parameter space where the
red-tilted power spectrum and sufficient baryon asymmetry are produced.} We
{find} that the non-Gaussianity parameter $f_{\rm NL} \gtrsim \mathcal{O}
(0.1)$ is produced for high-scale seesaw ($v_{B-L}$ at
$\mathcal{O}(10^{14-17})$ GeV) and leptogenesis ($M_1 \gtrsim
\mathcal{O}(10^6)$ GeV) where the latter represents the lightest right-handed
neutrino mass. While the current bounds on local non-Gaussianity excludes some
part of parameter space, the rest can be fully probed by future experiments
like CMB-S4, LSST, and 21 cm tomography.
