We report a nominally high-confidence \gamma -ray quasi-periodic modulation in the blazar PKS 0301 - 243 .
For this target , we analyze its Fermi -LAT Pass 8 data covering from 2008 August to 2017 May .
Two techniques , i.e. , the maximum likelihood optimization and the exposure-weighted aperture photometry , are used to build the \gamma -ray light curves .
Then both the Lomb-Scargle Periodogram and the Weighted Wavelet Z-transform are applied to the light curves to search for period signals .
A quasi-periodicity with a period of 2.1 \pm 0.3 yr appears at the significance level of \sim 5 \sigma , although it should be noted that this putative quasi-period variability is seen in a data set barely four times longer .
We speculate that this \gamma -ray quasi-periodic modulation might be evidence of a binary supermassive black hole .