Greg was born in Missoula, Montana and grew up north of Seattle in Lynnwood, Washington. After high school, Greg joined the United States Army Infantry and spent four years on active duty, including fifteen months in combat operations in support of Operation Iraqi Freedom. After his time on active duty, Greg returned to Montana, joining the Montana Army National Guard, and attending the University of Montana. Before graduating with his Bachelor of Science in Business Management, Greg was called up to deploy to Iraq again, this time in support of Operation New Dawn.

Upon his return, Greg was accepted into a joint degree program at the University of Montana where he simultaneously pursued his Juris Doctorate and Master of Business Administration. During law school, Greg continued to serve in the National Guard as an Officer Candidate School instructor and interned with notable Montana law firm Datsopoulos, MacDonald & Lind, P.C. Greg earned his J.D. and MBA, receiving the Clinical Student Award from faculty – hailing him the most qualified to practice before graduation.

Greg began his professional career with Datsopoulos, MacDonald & Lind, P.C. where he worked on a broad variety of legal matters involving complex and nuanced legal issues. Eventually, Greg joined Thomas Orr at his long-established Missoula firm. In 2019, Greg was offered a commission in the United States Army as a Judge Advocate General Corps attorney. Greg accepted the nomination and graduated from the Judge Advocate General’s School in Charlottesville, Viginia in 2020.

In 2021, Tom and Greg formed Orr McDonnell Law, PLLC to provide advice, counsel, and litigation services more effectively for clients in a ranging field of legal topics including torts, contracts, real estate, small business issues, and family law. Greg continues to serve in the Montana Army National Guard as a Judge Advocate in the role of Trial Defense Counsel. Greg has also been selected and approved by the Montana Supreme Court as substitute judge for the Missoula Municipal Court where he periodically serves as a judge.

Greg practices in all State of Montana Courts, the Montana Supreme Court, the U.S. District Court of Montana, the Ninth Circuit Court of Appeals, and the U.S. Court of Appeals for the Armed Forces. Greg is also authorized to practice before courts-martial, military boards, and trial-level military tribunals.

When not practicing law, Greg enjoys spending time with his wife and two boys, hunting, fishing, and being outdoors in Montana.