  The effect by which light focuses upon entering a medium with a negative
refractive index, known as Veselago lensing, may enable optical imaging below
the diffraction limit. Similarly, focusing electrons across a $pn$-junction
could realize a technologically promising electronic Veselago lens. However,
its scope remains limited by the lack of three-dimensional platforms and its
insensitivity to computational degrees of freedom, like spin or chirality. Here
we propose a single-material three-dimensional electronic Veselago lens that
selectively focuses electrons of a given chirality. Using the chiral anomaly of
topological semimetals it is possible to create a sharp $pn$-junction for a
single chirality, a chiral Veselago lens, and tune it with a magnetic field to
an ideal lensing condition. We estimate that chiral Veselago lensing is
observable in non-local transport and spectroscopy experiments. In particular
we show that the chiral Veselago lens leads to giant non-local
magnetoresistance.
