NBC's lone soap has hardly been a lock for renewal in recent years, but its ratings have been on the upswing.
In January, the Sony Pictures TV-produced show brought its most-watched week since the network was getting a boost from the 2014 Sochi Olympics, averaging 2.9 million viewers, said the Hollywood Reporter.
"NBC is incredibly proud of the legacy of Days of Our Lives and we couldn't be more excited to brings its fans new stories for the 51st season," NBC Entertainment president Jennifer Salke said in a statement.
"Days of Our Lives" is executive produced by showrunner Ken Corday, son of co-creators Ted and Betty Corday. In 2015, it earned the Daytime Emmy Award for outstanding drama series.