Christopher Word, 23, refused a request by his boss to remove the pin while at work.
A chamber spokesman said word was fired because he brought politics into the workplace.
"Last week, the executive director of the chamber, Bill Powell, personally observed Christopher Word use his position as an employee of the chamber as a platform to advocate his personal political views about former Alabama Chief Justice Roy Moore," said the chamber's attorney A.W. Bolt.
"In the course of my brief explanation of why I personally feel it's important that I wear it, I happened just to mention, briefly, the chief justice is a good friend of our family, and then I just went on to say it's an issue that I care a lot about," said Word.
Word's attorney said his client was denied his constitutional rights.