The field is being led by Amazon and its Alexa assistant. It will be available in late September. Consumers will be able to buy through voice with Google Assistant on Google Home or on the Google Express website or app.
The personalisation of the partnership with Walmart means people can shout out generic items like milk, bread and cheese, and Google Assistant will know exactly the brands and the size that the user wants.
"Voice shopping is becoming a more important part of everyday shopping behavior", said Marc Lore, CEO of Walmart's USA e-commerce business.
Walmart's partnership with Google isn't just about shopping by voice either. But that was far behind the Echo, available since late 2014. In a blog post announcing the partnership, Google mentions that "there's no membership required" to get free shipping - a dig at Prime.
Walmart also announced this week that it would partner with Uber in expanding its grocery-delivery services.
Amazon has also dominated Wal-Mart and other brick-and-mortar retailers in online sales.
It's also been drawing in customers with its Alexa-powered devices.
"We continue our transformation to become more of a digital enterprise that moves with speed and agility", Wal-Mart Chief Executive Officer Doug McMillon said last week during the company's pre-recorded call for investors. This new addition would make ideal sense as Amazon Echo Dot's are dotting (pardon our pun) the mini speaker landscape. Google is removing the $95 annual membership fee for the Express service and is going to offer free delivery as long as your order meets the minimum bill requirement.
Owners of the Google Home will be able to speak orders to their voice-activated Google Assistant (aka "Okay, Google") for delivery or pickup via its local online shopping marketplace Google Express. Walmart, meanwhile, doesn't have an Alexa rival on hand, even though it has a massive retail presence that rivals Amazon's. Whole Foods shareholders vote Wednesday on Amazon's offer to buy the organic foods grocer.
Next year, Dore says the company will offer different kinds of voice shopping experiences throughout its 4,700 stores in the U.S. This includes allowing customers to pick an order up inside a store or to purchase groceries across the country.