  We define functorial isomorphisms of parallel transport along \'etale paths
for a class of principal $G$-bundles on a $p$-adic curve. Here $G$ is a
connected reductive algebraic group of finite presentation and the considered
principal bundles are just those with potentially strongly semistable reduction
of degree zero. The constructed isomorphisms yield continous functors from the
\'etale fundamental groupoid of the given curve to the category of topological
spaces with a simply transitive continous right $G(\mathbb{C}_{p})$-action.
This generalizes a construction in the case of vector bundles on a $p$-adic
curve by Deninger and Werner. It may be viewed as a partial $p$-adic analogue
of the classical theory by Ramanathan of principal bundles on compact Riemann
surfaces, which generalizes the classical Narasimhan--Seshadri theory of vector
bundles on compact Riemann surfaces.
