High-strength strain-hardening cement-based composites (HS-SHCC) demonstrate excellent mechanical and durability properties. However, high cement content typical to HS-SHCC results not only in high carbon footprint, but also in excessive hydration heat and severe autogenous shrinkage. In this investigation, Limestone Calcined Clay Cement (LC³) was used to produce sustainable HS-SHCC. The LC³ substitution resulted in higher energy consumption during mixing and in shorter setting times of the fresh, plain matrices. Although the LC³ substitution slightly reduced the compressive strength, the formation of highly polymerized C-A-S-H gel and abundant ettringite benefited the flexural strength of the plain matrices. Additionally, single-fiber pullout experiments showed that the use of LC³ led to increased fiber-matrix bond strength and pullout energy. Finally, the replacement of Portland cement by LC³ resulted in HS-SHCC with similar mechanical performance to the reference composite, indicating a high potential for using LC³ in high-performance cement-based composites.