The Full Form of LMO is Labour Market Opinion.

A labour market opinion is a document issued by the Human Resources and Skills Development Canada agency that states that the hiring of a foreign worker has a positive or neutral effect on the Canadian labour market. You must apply for this opinion to hire most foreign workers, and your application must show there are no Canadian citizens or permanent residents available to fill the job. The application must show that you have recruited for the position for at least four weeks with no success. You must be willing to pay the foreign worker the same amount or more than you would pay a Canadian and you must agree that working conditions are the same or better than those provided for Canadians. You must convince the officer reviewing your application that there is a need to hire foreign workers and that you are not taking jobs away from Canadians. You must meet all of these conditions for your application to be approved. You should expect the time from when you fill out and submit your application until the time you receive a labour market opinion to take at least three months.