  Historically, the blazar population has been poorly understood at low
frequencies because survey sensitivity and angular resolution limitations have
made it difficult to identify megahertz counterparts. We used the LOFAR
Two-Metre Sky Survey (LoTSS) first data release value-added catalogue (LDR1) to
study blazars in the low-frequency regime with unprecedented sensitivity and
resolution. We identified radio counterparts to all $98$ known sources from the
Third \textit{Fermi}-LAT Point Source Catalogue (3FGL) or Roma-BZCAT
Multi-frequency Catalogue of Blazars ($5^{\mathrm{th}}$ edition) that fall
within the LDR1 footprint. Only the 3FGL unidentified $\gamma$-ray sources
(UGS) could not be firmly associated with an LDR1 source; this was due to
source confusion. We examined the redshift and radio luminosity distributions
of our sample, finding flat-spectrum radio quasars (FSRQs) to be more distant
and more luminous than BL Lacertae objects (BL Lacs) on average. Blazars are
known to have flat spectra in the gigahertz regime but we found this to extend
down to $144$ MHz, where the radio spectral index, $\alpha$, of our sample is
$-0.17 \pm 0.14$. For BL Lacs, $\alpha = -0.13 \pm 0.16$ and for FSRQs, $\alpha
= -0.15 \pm 0.17$. We also investigated the radio-to-$\gamma$-ray connection
for the $30$ $\gamma$-ray-detected sources in our sample. We find Pearson's
correlation coefficient is $0.45$ ($p = 0.069$). This tentative correlation and
the flatness of the spectral index suggest that the beamed core emission
contributes to the low-frequency flux density. We compare our sample
distribution with that of the full LDR1 on colour-colour diagrams, and we use
this information to identify possible radio counterparts to two of the four UGS
within the LDR1 field. We will refine our results as LoTSS continues.
