  Aims: During the Spectrum Roentgen Gamma (SRG)/ eROSITA all-sky surveys,
X-ray sources close to the South Ecliptic Pole (SEP) are observed almost every
4 hours. We aim to identify the sources exhibiting the most significant
long-term X-ray variability within 3 degrees of the SEP in the first three
surveys, and investigate their properties.
  Methods: We determined the variability significance of all sources observed
by eROSITA within 3 degrees of the SEP by using thresholds on the Bayesian
excess variance (SCATT_LO) and the maximum amplitude deviation (AMPL_SIG).
Sources exhibiting a variability significance above $3\sigma$ were subdivided
into likely Galactic and extragalactic sources, by using spectral and
photometric information of their optical counterparts. We quantified the X-ray
normalised excess variances of all variable sources, and also calculated the
periodograms of the brightest ones.
  Results: Out of more than $10^4$ X-ray sources detected by eROSITA within 3
degrees of the SEP, we identified 453 that exhibit significant X-ray
variability. SCATT_LO is significantly more sensitive to detecting variable
sources in this field, but AMPL_SIG helps provide a more complete variability
sample. Of those variable sources, 168 were classified as likely extragalactic,
and 235 as likely Galactic. The periodograms of most bright and variable
extragalactic sources are approximately described by an aliased power law
($P\propto\nu^{-\alpha}$) with an index of $\alpha\approx 1$. We identified a
potential tidal disruption event, and long-term transient sources. The stellar
X-ray variability was predominantly caused by bright X-ray flares from
coronally active stars.
