As is often the case in real estate, the answer to this question depends. Professional real estate practices, including who can sell real estate, are regulated by individual states and so vary from state to state. Accordingly, whether you need a high school diploma to become a real estate agent depends on what your state law says. The sole exception to this is if you are selling your own home. You are always free to sell your own home without the help of a real estate agent no matter your education level.
Most states don’t specifically require a high school diploma, though some do. More often, states require that you be at least 18 years of age. This is because real estate agents enter into contracts with clients and on behalf of clients, and most contracts are not enforceable against people under 18 years of age. (Before you get any silly ideas, most contracts for debt are enforceable against people under 18 years old.)
While a high school diploma may not be required in some states to become a real estate agent, there are some skills that are taught and learned in high school that can be beneficial to someone that is interested in becoming a real estate agent. Math, statistics and accounting courses can help future real estate agents to deal with the financial aspects that are required in real estate transactions. This can range from determining comparative market analysis to keeping track of deposits and down payments. As well, a real estate agent will need basic math to figure out the amount of his or her commissions.
English, history, speech and drama classes are also great preparatory classes for those who wish to become real estate agents. These classes help students to learn communication and speech skills that will be necessary for real estate agents to communicate with clients on a daily basis. Computer classes are also very helpful to refine those that wish to become real estate agents. In the modern age of technology it is the real estate agent that has advanced computer and technology skills that will far surpass those agents that do not posses these skills.
So while state licensing agencies set the rules as to whether or not a real estate licensee practicing real estate in their state needs a high school diploma, there are skills that can be learned in high school that are beneficial to real estate agents.