This study first provides general background on the public education system of Quebec, and the Canadian and Quebec legal systems. Legal background information includes: the classification of Canadian laws; the Common Law and Civil Law traditions of law, and the definitions of sources of law of each tradition; Quebec's bijurisdictional legal system; the court system of Quebec; Constitutional sources of law; and, the role of the Judiciary in Canadian education. This thesis is a documentary study of the sources of law which establish language of instruction rights in Quebec. Its purpose is to assist educators, students of education, and other lay persons of law to gain understanding of the legal bases upon which the Judiciary formulate decisions in matters of language of instruction. Common Law and Civil Law legislative and case law sources, which are applicable to Quebec, are identified and examined, and relevant sources presented. In addition to providing a summary for Common Law sources, and for Civil Law sources, a chronological summary is given, which reveals six main periods in the development of language of instruction provisions in Quebec. The conclusion is that the primary sources of law for language of instruction in Quebec are: s. 93 of the Constitution Act, 1867, and case law there under; and, the judicial interpretation and provisions of s. 23 of the Constitution Act, 1982. Future case law in Quebec may reveal s. 23 of the Canadian Charter of Rights and Freedoms, 1982 to be the most significant source of law for the preservation of minority English language instruction, institutions, and rights of management and control.