Title Existence and uniqueness of solutions for multi-term nonlinear fractional integro-differential equations Type of Research Article Keywords Caputo fractional derivative; fixed point theorem; multi-term nonlinear fractional differential equation Abstract In this manuscript, by using the fixed point theorems, the existence and the uniqueness of solutions for multi-term nonlinear fractional integro-differential equations are reported. Two examples are presented to illustrate our results. Researchers Dumitru Baleanu (First Researcher)، Sayyedeh Zahra Nazemi (Second Researcher)، Shahram Rezapour (Third Researcher)