In a constantly changing world, workforce diversity has become a common term in organizations to represent employee performance. The study sought to find out the effect of workforce diversity on employee performance in Hibret Manufacturing and Machine Building Industry of Ethiopia. In the context of the study, workforce diversity is defined as organizations that are heterogeneous in terms of age, gender, ethnicity and educational background. Given the current wave of globalization and the prevalence of diversity in Ethiopia the study aims to fill the perceived gaps on the area of the relationship between age, gender, ethnicity, educational background on employee performance in Hibret Manufacturing and Machine Building Industry of Ethiopia. The study employed explanatory research design with mixed data type. The study area was the 4 clustered industries with sample size of 384 which was taken using simple random sampling. Questionnaires were used for data collections tool and data analysis was done portraying using Robust mean compassion test and Mixed-effects GLM result for regression analysis for the relevant research objectives and the four hypotheses formulated in the study. The analysis was done using the software STATA v14.Inferential statistics was used to show up the effect between the independent variable (age, gender, ethnicity and educational background) and the dependent variable (employee performance).From the result of Mixed-effects GLM, it is observed that educational qualifications, age and gender has a significance positive influence on employee performance. While multicultural workforce (Ethnicity) has a significant negative influence on employee performance. Based on the finding, the study recommended that Hibret Manufacturing and Machine Building Industry of Ethiopia should have a careful management of diverse workforce and uphold diversity policies in order to enhance employee performance.