This paper is mainly concerned with the construction of new off-shell higher spin N=1 supermultiplets in three spacetime dimensions. We elaborate on the gauge prepotentials and linearised super-Cotton tensors for higher spin N=1 superconformal geometry and propose compensating superfields required to formulate off-shell massless higher spin supermultiplets. The corresponding gauge-invariant actions are worked out explicitly using an auxiliary oscillator realisation. We construct, for the first time, off-shell massive higher spin supermultiplets. The gauge-invariant actions for these supermultiplets are obtained by adding Chern–Simons like mass terms (that is, higher spin extensions of the linearised action for N=1 conformal supergravity) to the actions for the massless supermultiplets. For each of the massive gravitino and supergravity multiplets, we propose two dually equivalent formulations.