Collins moves to the agency from California, where he was the managing director of the integrated agency C4 Consulting.
In his new role, Collins will be responsible for extending Arc's digital remit, as it bids to take advantage of the substantial growth in the sector.
Diana Cawley, the deputy managing director at Arc, said: "Dan has had a highly successful career building agencies working with blue-chip brands. His extensive knowledge will be invaluable as Arc continues to grow, delivering integrated off- and online campaigns for brands. The US is at the forefront of digital marketing, and Dan's experience there will drive the Arc offer here in the UK."
Collins has more than 15 years' experience, mainly in the US, working in a number of global strategic integrated marketing roles.
Before joining C4, he was a global account director at USWeb/CKS (which became marchFIRST), an internet company with a list of clients that includes Microsoft, Virgin Music and Boeing.