In late 2020, almost a year after a deadly virus sweeps the world, Phil Miller is seemingly the only human survivor in the United States.

Despite being annoyed by each other, Carol believes it is their job as the last two survivors to repopulate the world, but insists Phil marry her so their children will not be born out of wedlock.

In season three, following a threatening encounter with paranoid and violent survivor Pat Brown, the original group moves to a self-sustaining office building in San Jose, California, where Melissa struggles with mental instability and Carol discovers a young boy living in the woods, whom they name Jasper.

As time passes, Erica gives birth to a girl named Dawn, and the group decides to leave the United States for Mexico after seeing a nuclear facility meltdown close to the office.

During a hunt for the missing Jasper, Phil and Todd end up meeting Karl at a jail, who poses as a jailer, but is in fact a cannibal.

Following a brief reunion with a recovered Mike, the original group then moves to Tapachula, only to be found and surrounded by dozens of underground survivors.

Although the series was cancelled in May 2018, four days after season 4 ended,[3] an August 2018 interview with series creator Will Forte revealed that the plan for the subsequent season was to have both groups of survivors live together and gain one another's trust before the original group – as asymptomatic carriers of the virus – inadvertently infected and killed the survivors who had quarantined for years underground.

[25] They approached longtime collaborator and former Saturday Night Live cast member Will Forte with the premise, who "took a spark to it and took it in his own direction", according to Miller.

[27] In addition to Forte's fascination with Life After People, similar films discussed while writing the show included The Omega Man, I Am Legend, and 28 Days Later.

[31][32][33] For its one-hour premiere, The Last Man on Earth received 5.75 million viewers with an average 2.4 rating among adults 18–49, making it the highest-rated broadcast series of the evening in that demographic.

The site's critical consensus is, "It may run out of steam before the season's over, but The Last Man on Earth's ambitious concept and comedic undertone are enough to lure viewers in.

[51] Hank Stuever of The Washington Post called it "a charming and intelligent sendup of pop culture's obsession with the end of everything".

[54] Entertainment Weekly's Jeff Jensen called it "profoundly funny", and sustainable if it continues the "ingenuity, surprises, and craftsmanship".

[29] "I was impressed by The Last Man on Earth, and hope it can continue to spin stories and character development out of its somewhat narrow premise", wrote Matthew Gilbert of The Boston Globe.

[55] Several critics, such as Maureen Ryan of The Huffington Post[9] and David Hinckley of the New York Daily News, have questioned the show's future.

[57] Brian Lowry of Variety opined that "the premise calls for a level of creativity from the producers that these episodes don't consistently deliver.