The agreement, announced in advance of the Cop26 summit in Glasgow in November, marked the first time the charity has teamed up with a UK power company in more than a decade.
The two organisations are now pledging to work together to accelerate the UK's transition to net zero and to call for ambitious climate action at the UN climate conference.
To mark the agreement, WWF's famous panda logo was projected on ScottishPower's Glasgow HQ, which overlooks the Cop26 venue.
Work will initially focus on cutting carbon from the housing - a sector which currently produces 14% of such emissions in the UK.
WWF and ScottishPower will undertake joint research into how the installation of low-carbon technologies, such as heat pumps and battery storage, could be used to add value to individual homes, as well as looking at how homeowners could be supported to make the upgrades more easily.
Tanya Steele, chief executive at WWF, said: "By working with ScottishPower, a climate leader in the UK's energy sector, we can provide expertise and solutions to help drive the UK's route to net zero.
"Time is running out and we need urgent action to reduce emissions for our own sake and that of future generations."
Keith Anderson, ScottishPower chief executive, said: "The work of WWF to highlight and address the climate crisis is truly inspiring and I'm incredibly proud that it recognises ScottishPower as a leader towards achieving a decarbonised future for the UK.
"We closed our coal plants, ditched gas generation and built onshore, offshore and solar generation and are investing £10 billion over five years to help deliver the changes needed to support net zero targets and the hope of keeping 1.5C - the goal to limit global warming - alive.
"To embrace a cleaner, greener future our cities, communities, businesses and governments all need to work together to innovate and find ways to do things differently, faster.
"By partnering with WWF and with Cop26 fast approaching, we want to show that looking after our planet is good for business and help create a net zero economy that's fair for all."