A timber-concrete composite (TCC) system consists of a timber member and a reinforced concrete slab with a shear connection at their interface. TCC systems offer many advantages compared to single-material schemes, including lighter floors, lower embodied carbon, and longer spans. A key design criterion for TCC floor systems is the deflection limit imposed by building codes. Long-term deformations in TCC systems are mainly due to the sustained long-term load (due to the viscoelasticity of concrete and timber) and changes in environmental conditions. Slip in the connection between timber and concrete can also increase under sustained loads over time. Therefore, when determining the final deflection of TCC systems, the long-term behaviour of the component materials and the connection should be considered. While there is a substantial knowledge base on the long-term behaviours of timber and concrete individually, knowledge of long-term deflection in TCC systems is limited. This study addresses this gap by investigating the long-term performance of selected TCC connections through a creep test programme. The tests will generate displacement versus time responses of TCC connections, leading to developing related creep coefficients that could be implemented in design standards. Further validation of the experimental results is planned via numerical modelling.