"We want to apologize," Amazon said in a message posted at its website.
"We know how critical our services are to our customers' businesses, and we know this disruption came at an inopportune time for some of our customers."
Amazon.com attributed the outage to a mistake by one of its developers that caused a problem with load balancers at data centers the company uses to provide "web services" to clients such as Netflix.
The "event" lasted from early Christmas Eve in California into Christmas morning, according to Seattle, Washington-based Amazon.
More than 27 million Netflix members in the Americas may have been unable to access shows or films online due to the problem at Amazon Web Services, which rents out computing power in datacenters in the Internet "cloud."
No problems were reported with viewing offerings at Amazon's rival online film service.
In a message fired off at Twitter, Netflix referred to the outage as "terrible timing." Netflix noted that users in Europe were not affected.
"We will do everything we can to learn from this event," Amazon said in its message.