Speaking at an event hosted by global bank HSBC, Hammond said around two-thirds of debt and equity capital raised by European Union (EU) corporations is facilitated by banks based in the United Kingdom (UK).
He said the financial services hub is an engine that powers the real economy not just in the UK, but all across Europe.
"So I am clear not only that it is possible to include financial services within a trade deal but that it is very much in our mutual interest to do so," Hammond added.
Josh Hardie, deputy director general of the Confederation of British Industry, said "trying to forge a new trading relationship with our largest trading partner that does not include financial services is like building a ship with no sails."
Hardie said protecting, maintaining and developing UK's world-beating financial services sector -- the lifeblood of both the UK's and the EU's economies -- enables all other sectors to deliver jobs, innovate and grow.