The news comes on the same day that Washington parted ways with team president Bruce Allen.
The Redskins hope the moves can revive a franchise that hasn't won a playoff game in 14 seasons and faces plummeting attendance.
Rivera becomes the seventh head coach hired by owner Dan Snyder. Because Rivera, 57, is a minority candidate, the Redskins could fulfill the Rooney Rule immediately. Carolina fired Rivera on Dec. 3 with a 5-7 record, and he was viewed as a strong candidate for any opening.
The Redskins fired Jay Gruden after an 0-5 start in his sixth season. Some players bemoaned a lack of discipline, something interim coach Bill Callahan said he wanted to correct.
Allen was the primary voice in Washington's football matters since the firing of coach Mike Shanahan in 2013. The Redskins hired Scot McCloughan as general manager after the 2014 season, but he was fired after the 2016 season, and Allen regained control. Snyder had hired Allen to be his top executive late in the 2009 season.
The team released a statement from Snyder on Monday morning regarding Allen's ouster:
"As this season concludes, Bruce Allen has been relieved of his duties as President of the Washington Redskins and is no longer with the organization. Like our passionate fan base, I recognize we have not lived up to the high standards set by great Redskins teams, coaches and players who have come before us. As we reevaluate our team leadership, culture and process of winning football games, I am excited for the opportunities that lie ahead to renew our singular focus and purpose of bringing championship football back to Washington D.C."
Now the team turns to Rivera. He'll try to revive a franchise that hasn't made the playoffs since 2015 and hasn't won a postseason game since 2005. Attendance at Washington home games has plummeted, and opposing fans often outnumber Redskins fans. Washington ranked 19th in the NFL in attendance and 30th in percentage of seats used this season.
Rivera quickly turned around the Panthers, who went 2-14 in 2010, the season before he took over. Three seasons later, they went 12-4. In 2015, they were 15-1 and reached the Super Bowl. Rivera compiled a 76-63-1 record with Carolina, although the Panthers had only three winning seasons in his eight full years. They reached the playoffs four times, including in 2014 with a 7-8-1 record, and won the NFC South three seasons in a row.
"He gets the best out of players," said cornerback Josh Norman, who played for Rivera in Carolina. "And not just players, but men. He builds men and guys and also builds character.''
Norman said the Redskins' culture would be entirely different with Rivera as head coach. It has been an issue with Allen in charge, and even quarterback Case Keenum on Monday said of the organization, "I think there are some cultural things that need to be addressed.''
Washington, meanwhile, has had quite a fall from grace for a franchise that played in five Super Bowls -- and won three -- between 1972 and 1991.
The franchise has been beset by conflicts; one former member of the Redskins' football department said the team would win again when the "non-football people stop making football decisions." Players have often complained about the overall culture at Redskins Park outside of the locker room. Among other things, they point to a facility that lags behind most in the NFL despite having been updated in recent years.
This season, a key storyline involved the holdout by seven-time Pro Bowl tackle Trent Williams. Allen didn't trade him by the Oct. 29 deadline, prompting Williams to report to the team -- but also to rip the franchise over a loss of trust stemming from medical issues. Williams later said he would not have said anything had the Redskins traded him; he had strong support from teammates.
It adds up to why the Redskins needed change. Sources said the Redskins knew they needed a strong leader, someone with previous head-coaching experience -- and who has had success.
Rivera had a reputation in Carolina for being firm with players but also for getting to know them beyond the field.
Rivera also was Chicago's defensive coordinator in 2006 when the Bears reached the Super Bowl. He served in the same role from 2008 to 2010 with the San Diego Chargers. Carolina hired him as its head coach in January 2011. With the Panthers, Rivera earned a reputation in his first two seasons for being conservative. But in 2013, he changed tactics and became known as "Riverboat Ron" for what others called gambling on specific playcalls; he referred to the decisions as "calculated risks."
In Washington, he'll inherit a team with plenty of young players, including quarterback Dwayne Haskins. By season's end, partly because of injuries, the Redskins had used 12 players age 25 or younger as consistent starters. Washington also owns the No. 2 pick in the 2020 NFL draft.
Allen had a legacy with the franchise. His father, George, coached the Redskins from 1971 to 1977, guiding the team to its first Super Bowl, where it lost to Miami. He had turned around a franchise that had floundered throughout the 1950s and '60s.
But his son could not duplicate that success from an executive position. Bruce Allen became a divisive figure for the fans. During his 10-year tenure, the Redskins won the NFC East twice but finished with double-digit losses five times and never won more than 10 games. They made just two playoff appearances, losing in the first round each time. The Redskins were 62-97-1 under Allen. After a four-year stretch in which they were a combined 31-32-1 with two injury-filled seasons, they plummeted to new lows in 2019. The Redskins' 3-13 record this season included eight losses by 10 or more points.
Allen was named the 2002 Sporting News Executive of the Year while with the Oakland Raiders. He joined the Tampa Bay Buccaneers in 2004 as a general manager but was fired after the 2008 season.
ESPN's John Keim and The Associated Press contributed to this report.