Originally, the municipality also included the southwestern tip of the large island of Senja.

It would link the main islands of Bjarkøy together with a bridge and undersea road tunnel enabling residents to drive further which would drastically shorten the ferry ride to the mainland in Harstad.

The prestegjeld (church parish) of Sand was established as a municipality on 1 January 1838 (see formannskapsdistrikt law).

In 1887, the church was moved to the island of Bjarkøya, so the municipal name was changed to Bjarkø.

The official blazon is "Azure, a demi-griffin passant Or" (Norwegian: I blått en halv gull griff).

This means the arms have a blue field (background) and the charge is a demi-griffin (upper half showing, no legs).

The griffin has a tincture of Or which means it is commonly colored yellow, but if it is made out of metal, then gold is used.

At the time of the municipal dissolution, it was part of the Trondenes prosti (deanery) in the Diocese of Nord-Hålogaland.

The highest point in the municipality is the 987-metre (3,238 ft) tall mountain Skjellesvikgalten on the island of Grytøya.

The municipal council (Kommunestyre) of Bjarkøy was made up of 13 representatives that were elected to four year terms.