  Unclonable cryptography utilizes the principles of quantum mechanics to
addresses cryptographic tasks that are impossible classically. We introduce a
novel unclonable primitive in the context of secret sharing, called unclonable
secret sharing (USS). In a USS scheme, there are $n$ shareholders, each holding
a share of a classical secret represented as a quantum state. They can recover
the secret once all parties (or at least $t$ parties) come together with their
shares. Importantly, it should be infeasible to copy their own shares and send
the copies to two non-communicating parties, enabling both of them to recover
the secret.
  Our work initiates a formal investigation into the realm of unclonable secret
sharing, shedding light on its implications, constructions, and inherent
limitations. ** Connections: We explore the connections between USS and other
quantum cryptographic primitives such as unclonable encryption and position
verification, showing the difficulties to achieve USS in different scenarios.
  **Limited Entanglement: In the case where the adversarial shareholders do not
share any entanglement or limited entanglement, we demonstrate
information-theoretic constructions for USS.
  **Large Entanglement: If we allow the adversarial shareholders to have
unbounded entanglement resources (and unbounded computation), we prove that
unclonable secret sharing is impossible. On the other hand, in the quantum
random oracle model where the adversary can only make a bounded polynomial
number of queries, we show a construction secure even with unbounded
entanglement.
  Furthermore, even when these adversaries possess only a polynomial amount of
entanglement resources, we establish that any unclonable secret sharing scheme
with a reconstruction function implementable using Cliffords and
logarithmically many T-gates is also unattainable.
