New methodologies involving the activation of inert C(sp2)-H bonds have provided an alternative and efficient way for arylations of arenes. In the past decade, a lot of advances on direct arylations have emerged in the context of Ru catalysis. However, the vast majority of these reports require elevated temperatures (80-120 Â°C). To this end, we present a regioselective method for o-functionalisation of N-heteroaryl arenes at room temperature with a Ru(ÎÎ) catalyst, induced by visible light. A variety of electron-withdrawing and electron-donating groups are compatible with this process. Preliminary mechanistic experiments point towards a mechanism that could involve visible-light mediated Î·6-arene decomplexation followed by cyclometalation and oxidative addition of an aryl halide to the Ru centre.