Features of the app include the ability to search, choose and book a hotel in a few steps, click-to-call functionality and a credit card scanner.
A push notification has also been included, giving app users first access to new special offers.
Meanwhile, the enhanced website has integrated all Radisson brands into one platform, where users can earn, view and redeem rewards points.
Eric De Neef, executive vice-president and global chief commercial officer, Radisson Hotel Group, said: “The launch of RadissonHotels.com is a key milestone on our journey towards the top. Having one single touchpoint for all our brands will strongly enhance the user experience and drive SEO value.
"RadissonHotels.com is a core commercial initiative of our five-year operating plan, which is transforming our business and aiming to make Radisson Hotel Group the company of choice for guests, owners and talent.”