Marjoram and thyme are both members of the mint family. Both are commonly used in Middle Eastern cuisine and in herb blends due to their mild flavor, according to Epicurious.com. They are also used in French, Mexican and Mediterranean dishes.
In many recipes, thyme and marjoram can be substituted for one another. They can sometimes be substituted for oregano, which is a wild relative of marjoram with a stronger taste. Both thyme and marjoram are used in the French herb blend called herbes de Provence. In Mexico, thyme, marjoram and oregano are combined in an herb blend called hierbas de olor.