Sinkholes are geo-hazards which can form suddenly without humanly visible pre-indication from soil surface settlement. An early warning system located below ground would enable to detect sinkhole-induced settlement before it reaches the surface, preventing possible damage to infrastructure and protecting lives. This paper focuses on the use of Distributed Fiber Optic Sensing (DFOS) as a solution for early detection of sinkhole formation. A series of small-scale experiments in controlled conditions are used to simulate the formation of a sinkhole. Fiber optics cables are laid in the soil specimen, and strains are collected using the LUNA ODiSi 6100 analyzer. The soil movements are observed through a Perspex window, collected with a camera and analyzed using Particle Image Velocimetry (PIV). Results indicate the ability of DFOS in detecting soil movements and underline the typical signature strain profile expected during sinkhole formation, indicating that at an early stage in the sinkhole formation, horizontal movements govern the strain profile within the cable. In conclusion, our study suggested that the DFOS technology can be used to detect, locate and estimate the size of a sinkhole, even though it has not possible to monitor the real strain level in the soil, due to a lack of shear transfer at the interface between the soil and the cable.