Ten-man Italy missed out on a third consecutive World Cup after losing their play-off on penalties to Bosnia and Herzegovina.
Having failed to reach Russia 2018 and Qatar 2022, Italy are the first former winners to miss out on three consecutive World Cups.
Newcastle's Sandro Tonali was the only player to score from the spot for the four-time winners as Bosnia and Herzegovina found the net with all four of their penalties after taking advantage of Alessandro Bastoni's first-half sending off.
Italy's defeat ensures their World Cup absence will stretch to at least 16 years, their last knockout match at the tournament coming against France in the 2006 final that they won on penalties.
The Azzurri have failed to progress from the group stages in their last two appearances and have since not even qualified.
The only other World Cup that Italy did not qualify for was in 1958.
"We still don't believe it - that we're out and that it happened in this manner," Italy defender Leonardo Spinazzola said.
"It's upsetting for everyone. For us, for our families, and for all the kids who have never seen Italy at a World Cup."
"I want to personally apologize since we didn't make it," head coach Gennaro Gattuso said. "Talking about my future is not important. Today it was important to get to the World Cup."
The front page of Italy's main daily newspaper lamented "the World Cup curse" and called for a rebuild.
"We realise we're in a huge crisis," Italian soccer federation president Gabriele Gravina said.
Gattuso's side were on course to progress when Moise Kean capitalised on an error from Bosnia goalkeeper Nikola Vasilj to claim a 15th-minute opener.
But, following Bastoni's 41st-minute dismissal for a last-man foul on Amar Memic, substitute Haris Tabakovic levelled in the 79th minute.
Bosnia's subsequent shoot-out victory sparked wild scenes, though manager Sergej Barbarez said: "I've never entered or finished a game calmer. I saw it in their eyes."
Bosnia and Herzegovina, who will play at a second World Cup following their debut in 2014, will be in Group B alongside co-hosts Canada, Qatar and Switzerland.
Viktor Gyokeres fired Sweden to this summer's tournament by claiming a late winner in a 3-2 success over Poland.
Goals from Nicola Zalewski and Karol Swiderski cancelled out efforts from Anthony Elanga and Gustaf Lagerbielke as Poland twice came from behind in Stockholm.
But Arsenal striker Gyokeres settled the playoff two minutes from time, rifling into the roof of the net after Besfort Zeneli's effort struck the right post.
Graham Potter's side will be in Group F in North America, alongside Netherlands, Japan and Tunisia.
The Czech Republic qualified for the World Cup for the first time in 20 years after overcoming Denmark 3-1 on penalties following a 2-2 draw after extra time.
Rasmus Hojlund, Anders Dreyer and Mathias Jensen missed from the spot for the Danes in Prague.
Pavel Sulc put Czech Republic ahead before Joachim Andersen nodded home to force an additional 30 minutes.
Ladislav Krejci's deflected finish restored the home side's lead, only for Kasper Hogh's header to take the tie to a shoot-out.
Czech Republic will play co-hosts Mexico, South Africa and South Korea in Group A.
Kosovo's dream of a World Cup debut was dashed by a 1-0 home defeat to Turkey.
Kerem Akturkoglu's 53rd-minute goal was the difference in Pristina, with Turkey progressing to Group D, which contains co-hosts the United States, Paraguay and Australia.
The Democratic Republic of Congo qualified for their first World Cup since 1974 after beating Jamaica 1-0 in their intercontinental playoff final in Mexico on Tuesday.
The game went to extra time after ending goalless, despite DR Congo striker Cedric Bakambu having two earlier efforts ruled out for offside by the Video Assistant Referee, before Burnley defender Axel Tuanzebe finally scored a 100th-minute winner at the Guadalajara Stadium.
As a result, DR Congo have progressed to this summer's tournament, where they will line up alongside Portugal, Colombia and Uzbekistan in Group K.
And joining them in the United States will be Iraq, who became the 48th and final nation to qualify for the World Cup after beating Bolivia 2-1 in their intercontinental playoff on Tuesday.
Goals from Ali Al-Hamadi and Aymen Hussein mean Graham Arnold's side will take part in their first World Cup since 1986, where they will join the likes of France, Senegal and Norway in Group I.
