The present study aims to find out the relationship between the Conscientiousness trait and English Language Learning Strategies (ELLSs) for learners of English as a foreign language. Four instruments were used, which were Persian adapted Strategy Inventory for Language Learning (SILL), A Background Questionnaire, NEO-Five Factors Inventory (NEO-FFI), and Test of English as a Foreign Language (TOEFL). Two hundred and thirteen Iranian female university level learners of English language as a university major in Iran, were volunteer to participate in this research work. The intact classes were chosen. The results show that there is a significant relationship between the Conscientiousness trait and use of the each of six categories of ELLSs.