We compute the conformal blocks associated with scalar-scalar-fermion-fermion
4-point functions in 3D CFTs. Together with the known scalar conformal blocks,
our result completes the task of determining the so-called `seed blocks' in
three dimensions. Conformal blocks associated with 4-point functions of
operators with arbitrary spins can now be determined from these seed blocks by
using known differential operators.Comment: 25 pages; V2: added small clarifications to match JHEP versio