An object complement is an noun, pronoun, or adjective which follows a direct object and renames it or tells what the direct object has become. It is most often used with verbs of creating or nominating such as make, name, elect, paint, call, etc.

We know there is a difference between calling Mayor Williams and calling Williams mayor or painting a red door and painting a door red. When the word follows the direct object and it tells what the direct object has become, it is the object complement. Sometimes people call it an objective complement. The italicized words on this page are object complements.

Some more examples

I made my sister angry. (The one who's angry is the sister) Object complement, better known as O.C

I painted my house red (Red is an adjective that's moddifying the word house) =O.C

I called my baby girl Sophie (Sophie is a proper noun that's adding more info about the baby girl and is also a O.C