This study is on the language of oppression and quest for justice in Kithaka wa Mberia‟s plays. The plays are set in post-colonial Kenya, and oppression appears to be the dominant theme. The study identifies different language devices used in the plays and how they manifest in addressing oppression and quest for justice. A close reading of the plays shows a significant relationship between language and oppression. It also reveals language as a tool for protest against oppression. Deploying formalism, this study demonstrates that words and how they are used can enhance oppression or justice. Postcolonial theories are used to address the binary opposition between the oppressor and the oppressed, as well as to identify the subaltern groups in society. This theoretical perspective also establishes the voices that speak for the subaltern in the contemporary society.