[2] Orrington was originally part of Condustiegg or Kenduskeag Plantation,[dubious – discuss] which also included the present-day cities of Bangor and Brewer.

Orrington was incorporated as a town in 1788 with its major village at Brewer, then called "New Worcester".

The Boston & Penobscot Shipbuilding Company yard was on Mill Creek, South Orrington.

ice cut from the Penobscot River was shipped as far away as the British West Indies.

[1] While the Bangor area is served by two commercial bus carriers, it does not include service to Orrington.

Rail connecting Bucksport to Brewer runs through Orrington along the shore of the Penobscot River with a spur line to the former HoltraChem site.

[4] Orrington was home to the HoltraChem plant, which occupied 235 acres alongside the Penobscot River.

[4] As of 2002, the Penobscot Energy Recovery Corporation (PERC) waste-to-energy incinerator remained the only industrial employer (82 people).

The HoltraChem site itself was heavily contaminated, and cleanup was ordered by and as of 2022 is overseen by the Maine Department of Environmental Protection.

[6] In 2000, the Maine People’s Alliance and NRDC filed a lawsuit against Mallinckrodt US LLC, the successor to the plant’s first corporate owner.

In March 2021, a settlement submitted to a federal district court started the process of a river cleanup plan, long-term monitoring, and funding for projects to benefit communities affected by the pollution.