We analytically work out the orbital effects induced by the post-Newtonian gravitomagnetic spin-octupole moment of an extended spheroidal rotating body endowed with angular momentum S and quadrupole mass moment J 2 . Our results, proportional to GS J 2 c −2 , hold for an arbitrary orientation of the body's symmetry axisŜ and a generic orbital configuration of the test particle. Such effects may be measurable, in principle, with a dedicated spacecraft-based mission to Jupiter. For a moderately eccentric and fast path, the gravitomagnetic precessions of the node and the pericentre of a dedicated orbiter could be as large as 400 milliarcseconds per year or even 1, 600−4, 000 milliarcseconds per year depending on the orientation of its orbital plane in space. Numerical simulations of the Earth-probe range-rate signal confirm such expectations since its magnitude reaches the 0.03−0.3 millimetre per second level after just 1 day. The precision of the current two-way Ka-band Doppler measurements of the spacecraft Juno, presently orbiting Jupiter, amounts to 0.003 millimetre per second after 1, 000 seconds. Other general relativistic effects might be measurable, including also those proportional to GMJ 2 c −2 , never put to the test so far. Most of the competing Newtonian signals due to the classical multipoles of the planet's gravity field have quite different temporal signatures with respect to the post-Newtonian