The contemporary Sherlock Holmes drama stars Jonny Lee Miller as Conan Doyle's detective and Lucy Liu as his partner Joan Watson.
© PA Images
© CBS
Harbour will play the role of Dr. Mason Baldwin, TVLine reports.
The surgeon will assist Sherlock (Miller) when he is hired to investigate a murder in a hospital.
38-year-old Harbour recently appeared in four episodes of HBO's The Newsroom and also starred in short-lived ABC drama Pan Am.
His film credits include 2008's Revolutionary Road, the same year's James Bond movie Quantum of Solace and Madonna's 2011 directorial effort W.E..
Elementary - which will air on Sky Living in the UK - also stars Aidan Quinn (Prime Suspect) and Jon Michael Hill (Eastbound & Down).
The series will make its US debut on September 27 on CBS.
> Benedict Cumberbatch 'cynical' about US Sherlock series Elementary
> Elementary: Anika Noni Rose cast as former friend of Lucy Liu's Watson
Watch an Elementary preview below:
