  We present six epochs of spectropolarimetric observations and one epoch of
spectroscopy of the Type Ib SN iPTF 13bvn. The epochs of these observations
correspond to $-$10 to $+$61 days with respect to the {\it r}-band light curve
maximum. The continuum is intrinsically polarised to the $0.2-0.4\%$ level
throughout the observations, implying asphericities of $\sim10\%$ in the shape
of the photosphere. We observe significant line polarisation associated with
the spectral features of Ca II IR3, He I/Na I D, He I {\lambda}{\lambda}6678,
7065, Fe II {\lambda}4924 and O I {\lambda}7774. We propose that an absorption
feature at $\sim 6200\mathrm{\AA}$, usually identified as Si II $\lambda 6355$,
is most likely to be high velocity $\mathrm{H\alpha}$ at $-16,400$ $\mathrm{km
\; s^{-1}}$. Two distinctly polarised components, separated in velocity, are
detected for both He I/Na I D and Ca II IR3, indicating the presence of two
discrete line forming regions in the ejecta in both radial velocity space and
in the plane of the sky. We use the polarisation of He I $\lambda 5876$ as a
tracer of sources of non-thermal excitation in the ejecta; finding that the
bulk of the radioactive nickel was constrained to lie interior to $\sim
50-65\%$ of the ejecta radius. The observed polarisation is also discussed in
the context of the possible progenitor system of iPTF 13bvn, with our
observations favouring the explosion of a star with an extended, distorted
envelope rather than a compact Wolf-Rayet star.
