  We present the basic $\mathcal{N} =1$ superconformal field theories in
four-dimensional de Sitter space-time, namely the non-abelian super Yang-Mills
theory and the chiral multiplet theory with gauge interactions or cubic
superpotential. These theories have eight supercharges and are invariant under
the full $SO(4,2)$ group of conformal symmetries, which includes the de Sitter
isometry group $SO(4,1)$ as a subgroup. The theories are ghost-free and the
anti-commutator $\sum_\alpha\{Q_\alpha, Q^{\alpha\dagger}\}$ is positive. SUSY
Ward identities uniquely select the Bunch-Davies vacuum state. This vacuum
state is invariant under superconformal transformations, despite the fact that
de Sitter space has non-zero Hawking temperature. The $\mathcal{N}=1$ theories
are classically invariant under the $SU(2,2|1)$ superconformal group, but this
symmetry is broken by radiative corrections. However, no such difficulty is
expected in the $\mathcal{N}=4$ theory, which is presented in appendix B.
