  The sensitivity and angular resolution of photometric surveys executed by the
Hubble Space Telescope (HST) enable studies of individual star clusters in
galaxies out to a few tens of megaparsecs. The fitting of spectral energy
distributions (SEDs) of star clusters is essential for measuring their physical
properties and studying their evolution. We report on the use of the publicly
available Code Investigating GALaxy Emission (CIGALE) SED fitting package to
derive ages, stellar masses, and reddenings for star clusters identified in the
Physics at High Angular resolution in Nearby GalaxieS-HST (PHANGS-HST) survey.
Using samples of star clusters in the galaxy NGC 3351, we present results of
benchmark analyses performed to validate the code and a comparison to SED
fitting results from the Legacy ExtraGalactic Ultraviolet Survey (LEGUS). We
consider procedures for the PHANGS-HST SED fitting pipeline, e.g., the choice
of single stellar population models, the treatment of nebular emission and
dust, and the use of fluxes versus magnitudes for the SED fitting. We report on
the properties of clusters in NGC 3351 and find, on average, the clusters
residing in the inner star-forming ring of NGC 3351 are young ($< 10$ Myr) and
massive ($10^{5} M_{\odot}$) while clusters in the stellar bulge are
significantly older. Cluster mass function fits yield $\beta$ values around -2,
consistent with prior results with a tendency to be shallower at the youngest
ages. Finally, we explore a Bayesian analysis with additional
physically-motivated priors for the distribution of ages and masses and analyze
the resulting cluster distributions.
