Seattle, Indianapolis, Atlanta and Pittsburgh clinched division titles Sunday, while Green Bay grabbed the final wild-card berth.
The Seahawks, at 7-9, became the first division winner with a losing record in NFL history when they defeated St. Louis 16-6 for the NFC West championship.
"We didn't get here the way we all dreamed of getting here, but we got here," first-year coach Pete Carroll said. "When it came down to it, the guys played a great football game tonight."
The Packers beat archrival Chicago 10-3 to secure the NFC's sixth seed; defending league champion New Orleans has the conference's other wild card.
A last-second 43-yard field goal by the always-clutch Adam Vinatieri lifted the AFC South champion Colts past Tennessee 23-20.
Indy was already assured of its seventh division crown in eight years when the Jacksonville Jaguars lost to the Houston Texans minutes earlier. It's the ninth straight year the Colts have reached the post-season, tying the NFL record Dallas set from 1975-83.
"I think it shows the resolve of this team and our fight," Colts defensive end Dwight Freeney said. "It doesn't matter if we're 6-6 and we have to win our last four, we have to do it. If we have to win the last seven, we'll try to do it. That's just kind of what we are and we've been that for a while."
So Indianapolis (10-6) hosts the New York Jets (11-5) in a rematch of last January's AFC championship game on Saturday night. Before that, the Saints (12-4) are at Seattle.
On Sunday, NFC East champion Philadelphia (10-6) hosts Green Bay (10-6) after AFC West winner Kansas City (10-6) is at home against Baltimore (12-4).
Atlanta (13-3) won the NFC South with a 31-10 rout of Carolina. The Falcons get home-field advantage throughout the playoffs and a bye next week. They open their post-season the weekend of Jan. 15-16 in the Georgia Dome.
"It's very important," top receiver Roddy White said. "We rarely lose in this building. We find a way to win here."
Indeed, the Falcons are 20-2 at home with quarterback Matt Ryan as a starter.
The Steelers (12-4) took the AFC North with a 41-9 romp at Cleveland (5-11). They edged Baltimore in the division, making the Ravens a wild card. Pittsburgh is the No. 2 seed behind New England in the AFC and will have a bye next weekend.
"We love to win the division," Ben Roethlisberger said. "This is a hard division. We hope this is just the beginning."
New England already owned the top seed in the AFC and beat Miami 38-7 to finish 14-2, the league's best record. The Patriots won their last eight games.
"The greatest advantage we have is we don't have to play next week and we play at home the following week," Tom Brady said, "so that's really what we've earned to this point. I don't think we've earned anything more than that."
When Kansas City was ripped by Oakland 31-10, it gave the Colts the chance to become the No. 3 seed.
"I'm disappointed we lost, but we've got to bounce back," Chiefs running back Jamaal Charles said. "We've got another week going. The Raiders don't."
Baltimore defeated Cincinnati 13-7 to finish its season, while the Jets routed Buffalo 38-7.
Ravens star linebacker Ray Lewis doesn't care where his team has to travel.
"I think one reason why, for us, it never matters, is because our defence, we travel very well on the road," Lewis said. "We play extremely well on the road."
They were 5-3 away from home this season. They also won a wild-card game at New England last year. The previous season, the Ravens won at Miami and Tennessee in the playoffs.
The Jets won two post-season road games last year before falling short of the Super Bowl when the Colts stopped them.
"We are ready to go do what we set out to do," coach Rex Ryan said. "If somebody is going to beat us, then they must be really good."
Also in the playoffs from the NFC is Chicago (11-5), which owns the North title and the conference's other bye. Green Bay finished second in the division and got the final wild card on tiebreakers over Tampa Bay and the New York Giants, a pair of 10-6 teams that didn't qualify. The last time that happened in the NFC was 1991.
"Tonight was a struggle, but it's nice to keep that momentum going," Aaron Rodgers said after the win against the Bears. "We've won two in a row and now we've got to go [on the road]. And we can't have the kind of inconsistent performances we've had this year that have forced us to be the No. 6 seed."
The divisional round lineup will have Pittsburgh at home Saturday afternoon, Jan. 15, followed by Atlanta hosting a night game. On Jan. 16, Chicago hosts the early game, followed by a game at New England.