  Context. Knowing the rotation rates and masses of white dwarf stars is an
important step towards characterising the angular momentum transport mechanism
in their progenitors, and coupling the cores of red giants to their envelopes.
However, deriving these rotation rates is not an easy task. One can use the
rotational broadening of spectral lines, but there is another way to gather
reliable information on the stellar rotation periods of pulsators: through
studying the splitting effect of rotation on oscillation frequencies.
  Aims. We aim to derive stellar rotation periods in the TESS sample for as
many white dwarf pulsators as possible.
  Methods. We rely on light-curve analysis of the TESS observations, and search
for closely spaced frequency multiplets that could be rotationally split
pulsation modes. We work with triplet frequencies, even if one or two triplet
components are only marginally detectable. We also utilise ground-based
observations available from the literature in an attempt to confirm the
presence of several triplets.
  Results. We successfully identified rotationally split multiplets and derived
rotation rates for 14 stars. The fastest rotators we identified have rotation
periods of 6.6-10.0 h. The majority of the pulsators rotate with periods of
11.9-47.5 h, while we derived 85.5 and 93.2 h periods for the slowest rotators.
In addition to providing stellar mass estimations, our results confirm previous
findings that larger-mass WDs rotate faster than their lower-mass counterparts.
We determine the rotation periods of four stars for the first time.
