Flexible temperature sensors are crucial for applications in healthcare, IoT, and industrial fields due to their ability to measure temperature on curved surfaces and human skin. Recent advancements focus on materials like carbon nanomaterials, conductive polymers, metals, and metal oxides, which offer high sensitivity, fast response, and flexibility. Carbon nanotubes (CNTs) and graphene are prominent due to their excellent electrical and mechanical properties, though challenges remain in achieving uniform dispersion and flexibility. Conductive polymers like PEDOT:PSS provide good sensitivity and flexibility but require optimization for stability and temperature range. Metal oxides, such as NiO, offer high sensitivity and adjustability but face limitations in flexibility. Transition metal sulfides (TMS) like Ag₂S and MoS₂ show high temperature sensitivity and fast response times, making them promising for flexible sensors. Flexible substrates like polyimide (PI), polyurethane (PU), and hydrogels are essential for ensuring sensor flexibility and compatibility with biological tissues. Despite progress, challenges remain in balancing sensitivity, flexibility, and stability, with future research aiming to enhance these properties for commercial applications. The market for flexible electronics is growing rapidly, driven by IoT and AI, highlighting the importance of developing reliable and versatile flexible temperature sensors.Flexible temperature sensors are crucial for applications in healthcare, IoT, and industrial fields due to their ability to measure temperature on curved surfaces and human skin. Recent advancements focus on materials like carbon nanomaterials, conductive polymers, metals, and metal oxides, which offer high sensitivity, fast response, and flexibility. Carbon nanotubes (CNTs) and graphene are prominent due to their excellent electrical and mechanical properties, though challenges remain in achieving uniform dispersion and flexibility. Conductive polymers like PEDOT:PSS provide good sensitivity and flexibility but require optimization for stability and temperature range. Metal oxides, such as NiO, offer high sensitivity and adjustability but face limitations in flexibility. Transition metal sulfides (TMS) like Ag₂S and MoS₂ show high temperature sensitivity and fast response times, making them promising for flexible sensors. Flexible substrates like polyimide (PI), polyurethane (PU), and hydrogels are essential for ensuring sensor flexibility and compatibility with biological tissues. Despite progress, challenges remain in balancing sensitivity, flexibility, and stability, with future research aiming to enhance these properties for commercial applications. The market for flexible electronics is growing rapidly, driven by IoT and AI, highlighting the importance of developing reliable and versatile flexible temperature sensors.