OMERS, officially the Ontario Municipal Employees Retirement System, is a pension fund created by statute in 1962 to handle the retirement benefits of local government employees in the Canadian province of Ontario. It has become one of the largest institutional investors in Canada. Over the past 20 years approximately two-thirds of the capital added to the pension fund has been through investment returns, while about 1/3 has been added by contributions split evenly between employees and employers. , OMERS had 65.1 billion Canadian dollars in net investment assets. OMERS serves 982 employers and almost 440,000 members, retirees and survivors, including municipal workers, firefighters, police, emergency services staff, Children's Aid Society workers, school board staff (non-teaching), and transit and hydro workers.

The omer is an ancient Israelite unit of dry measure used in the era of the Temple in Jerusalem. It is used in the Bible as an ancient unit of volume for grains and dry commodities, and the Torah mentions as being equal to one tenth of an ephah. The ephah was defined as being 72 logs, and the Log was equal to the Sumerian mina, which was itself defined as one sixtieth of a maris; the omer was thus equal to about of a maris. The maris was defined as being the quantity of water equal in weight to a light royal talent, and was thus equal to about 30.3 litres, making the omer equal to about 3.64 litres.