The Legislative Assembly of Ontario (OLA; French: Assemblée législative de l'Ontario) is the legislative chamber of the Canadian province of Ontario. Its elected members are known as Members of Provincial Parliament (MPPs). Bills passed by the Legislative Assembly are given royal assent by the lieutenant governor of Ontario to become law. Together, the Legislative Assembly and Lieutenant Governor make up the unicameral Legislature of Ontario. The assembly meets at the Ontario Legislative Building at Queen's Park in the provincial capital of Toronto.
Ontario uses a Westminster-style parliamentary government in which members are elected to the Legislative Assembly through general elections using a "first-past-the-post" system. The premier of Ontario (the province's head of government) holds office by virtue of their ability to command the confidence of the Legislative Assembly, typically sitting as an MPP themselves and lead the largest party or a coalition in the Legislative Assembly. The largest party not forming the government is known as the Official Opposition, its leader being recognized as leader of the Opposition.