The deal, announced at the Consumer Electronics Show in Las Vegas, will see a Google icon built into internet-ready Motorola phones. The first models will be out in the first quarter of this year.
"Access to information is imperative for people on the go. Whether checking the local weather or locating a restaurant, consumers require personalised search services tailored to their needs," said Nikesh Arora, vice president of European operations at Google.
"With immediate access to Google, millions of Motorola users worldwide will be able to quickly and easily find information that's important to them."
But other software houses have warned that the deal may not be in the mobile phone manufacturers' best interests.
"The mobile industry must seriously think through the implications of this development," said Mike Brady, senior director of business development at enterprise search firm Fast.
"Google is not just a search engine; it's a global brand right up there with Coca-Cola. By partnering with Google, Motorola is allowing its own brand to be diluted.
"It might seem a smart move in the short term, but this will definitely impede future business models and revenue potential."
Latest Tesla news: Tesla stock price tanks amid reports of 'widening probe' by SEC and claims the base Model 3 loses money
SEC 'probe' takes its toll on Tesla as new research suggests that Tesla loses $6,000 on every $35,000 Model 3
10nm Cannon Lake Core i3-8121U CPUs make a rare outing with Intel's NUC mini PC
'Notorious' Australian child hacker thought he had executed 'flawless' hack
The former employee says that Tesla fired him for bringing the accusations to management internally