  We develop geometric superspace settings to construct arbitrary higher
derivative couplings (including R^n terms) in three-dimensional supergravity
theories with N=1,2,3 by realising them as conformal supergravity coupled to
certain compensators. For all known off-shell supergravity formulations, we
construct supersymmetric invariants with up to and including four derivatives.
As a warming-up exercise, we first give a new and completely geometric
derivation of such invariants in N=1 supergravity. Upon reduction to
components, they agree with those given in arXiv:0907.4658 and arXiv:1005.3952.
We then carry out a similar construction in the case of N=2 supergravity for
which there exist two minimal formulations that differ by the choice of
compensating multiplet: (i) a chiral scalar multipet; (ii) a vector multiplet.
For these formulations all four derivative invariants are constructed in
completely general and gauge independent form. For a general supergravity model
(in the N=1 and minimal N=2 cases) with curvature-squared and lower order
terms, we derive the superfield equations of motion, linearise them about
maximally supersymmetric backgrounds and obtain restrictions on the parameters
that lead to models for massive supergravity. We use the non-minimal
formulation for N = 2 supergravity (which corresponds to a complex linear
compensator) to construct a novel consistent theory of massive supergravity. In
the case of N = 3 supergravity, we employ the off-shell formulation with a
vector multiplet as compensator to construct for the first time various higher
derivative invariants. These invariants may be used to derive models for N = 3
massive supergravity. As a bi-product of our analysis, we also present
superfield equations for massive higher spin multiplets in (1,0), (1,1) and
(2,0) anti-de Sitter superspaces.
