  In the standard interaction scenario, a direct measurement of absolute
neutrino masses via neutrino oscillations is not feasible, as the oscillations
depend only on the mass-squared differences. However, the presence of scalar
non-standard interactions can introduce sub-dominant terms in the oscillation
Hamiltonian that can directly affect the neutrino mass matrix and thereby
making scalar NSI a unique tool for neutrino mass measurements. In this work,
for the first time, we constrain the absolute masses of neutrinos by probing
scalar NSI. We show that a bound on the lightest neutrino mass can be induced
in the presence of scalar NSI at DUNE. We find that the lightest neutrino mass
can be best constrained with $\eta_{\tau\tau}$ and $\eta_{\mu\mu}$ at $2\sigma$
C.L. for normal and inverted hierarchy respectively. This study suggests that
scalar NSI can serve as an interesting avenue to constrain the absolute
neutrino masses in long-baseline neutrino experiments via neutrino
oscillations.
