Please, gentle Eva, Will you bless a little child? For I love you, Tell Heaven I'm doing my best, I'm praying for you, Even though you're already blessed.
— "Santa Evita", from Evita by Andrew Lloyd Webber and Tim Rice
A cult of personality refers to massive adulation of a political or historical figure. The Other Wiki defines it as "when an individual uses mass media, propaganda, or other methods, to create an idealized, heroic, and, at times god-like public image, often through unquestioning flattery and praise." Often the subjects of cults of personality are treated as gods, held responsible for the good things affecting a country. The cult may often claim outlandish accomplishments for the subject in order to bolster their popularity. On the other hand, heroic stories about the subject's life may be endlessly repeated in order to reinforce the cult.
The word "cult" is usually used to refer to a small religious group, but it can also mean "devotion to a saint" in Christianity and this is where the phrase come from. It was first used in a political sense by Karl Marx, but was popularised by Nikita Khrushchev when he denounced Stalin in 1956.
A common feature of dictatorships such as Nazi Germany, North Korea, Peoples Republic of China and Stalinist Russia.
George Orwell's 1984 created "Big Brother," who was always watching. Citizens were brainwashed to love him as a father figure and devote their lives to his glory.
Frank Herbert intended Dune to be a deconstruction of this (and in the process invoking another trope), with Paul Muad'dib becoming trapped by the popular perceptions of him, leading to his Fallen Hero status and his son Leto becoming a literally inhuman tyrant for thousands of years.
Ironically, the book itself has almost become one, some fans call it the "sci-fi bible." The book has gone on to be considered an absolute masterpiece.
The Horatio race in Endless Space is a race made entirely of billions of clones of one insane rich man. He's essentially worshipped by them, to the point that one available hero is a Horatio that escaped being destroyed for being "aberrant" due to having similar qualities to him.
The BioShock series uses this, somewhat with Rapture's Andrew Ryan, but most prominently with Columbia's Zachary Comstock, who uses giant posters, statues, buildings, and audio messages to spread his message and paint himself as an all knowing Holy man.
In Super Dangan Ronpa 2, it is revealed that the students, save for Nanami, were members of Ultimate Despair, a personality cult devoted to the original Ultimate Despair herself, Junko Enoshima. Such was their devotion that when Junko died, the surviving Ultimate Despair members chopped up her body and replaced their own body parts with hers. One member (thought to be Kuzuryuu) took one of her eyes in order to 'see her despair', while Nagito Komaeda chopped off his hand and attached one of her hands to the stump.
Implemented by Timmy's Dad in The Fairly Oddparents episode "Father Time". Timmy destroys his father's childhood trophy with heat vision so he goes back in time to stop his dad from winning the race that got him the trophy in the first place. Timmy succeeds but his father is sent to Dictator School as punishment for losing the race and Timmy returns to his time to find that his dad now rules the world, and forces everyone to only think happy thoughts, always smile, and call him "father", reinforcing this with video surveillance and billboards claiming that "Dad is always watching!"
Dad: "Aaaaand here's where I'd put my trophy... IF I HAD ONE!"
In "The Simpsons" episode "Kiss Kiss Bang Bangalore", Homer travels to India after the Nuclear Plant is outsourced, where he becomes corrupted and takes over, establishing himself as a God. The rest of the family travel to India where they meet Mr. Burns, who takes them in his boat to the plant. When they reach the plant, they find all of the workers chanting to Homer and that they have painted his face on a large silo. Homer is dressed like Mola Ram from Temple of Doom and the workers are bowing to him as he sits on a throne. Turns out they just liked Homer's American Labor benefits of personal days, coffee breaks, and "mylar balloons on your birthday."
A lot of religious cults have created a literal cult of personality around their leaders.
The Soviet Union elevated their founder, Lenin, to almost divine stature. Countless statues, paintings, streets, cities were named after him. His corpse was mummified and put on permanent display in Moscow.
Subverted in that Lenin did not like icons. His wife would say after his death that "All his life, Vladimir fought against icons and now he's become an icon himself". Then there's Stalin, who created the cult of personality to Lenin and made one for him as well. Ships, cities, buildings, and a prize (the Order of Stalin, which was later renamed Order of Lenin) were named after him. After his death, Nikita Kruschev made a process to de-stalinize the Soviet Union, so statues and cities were destroyed and renamed and only the cult of Lenin survived.
Unsurprisingly, Hitler made one for him. Squares, ships and the like would be named after him.
In North Korea dictators Kim Il Sung and Kim Jong-Il are worshipped as gods. Literally! There are giant statues of them everywhere and almost every activity is done in celebration of the "Great Leaders". Of course, their corpses are also mummified and put on display.
In China, Mao Zedong used to be the center of a Cult Of Personality. Though still held in high regard and also mummified and put on display, the worship is not as fanatical as during his lifetime.
In The United States George Washington and Abraham Lincoln are certainly eligible for being featured on this page. They are highly regarded by many Americans as the most perfect presidents they ever had, to the point that Washington is believed to have "never told a lie" and Lincoln is nicknamed "Honest Abe".
Michael Jackson is a non-political example. Quite a few pop stars have been elevated to legendary proportions by their fans, especially if they died relatively young — Elvis Presley was the most prominent example for decades, followed closely by John Lennon. By comparison, Jackson actively cultivated this trope in his lifetime, pushing the Forced Meme of "The King of Pop" and casting himself as a great humanitarian and Friend to All Children. (Consider this.) Moreover, he encouraged fans to regard anything negative reported about him as nothing more than persecution by the sinister mass media. This worked; after his death they went publicly berserk, and the mythologizing around him only continues to grow, as do Conspiracy Theories and harassment/demonization of those perceived as his enemies.
As generations of British school children will tell you: British teachers have created a cult of personality around William Shakespeare. Every pupil has been forced to appreciate Shakespeare's genius over the centuries.