As the title suggests, in Justice League Endless Winter, the Frost King plunges the world into one.
The Crisis Crossover Final Night had an endless winter caused by the Sun-Eater.
Wonder Woman Vol 1: Princess Snowina has to keep her abode an endless winter, and approves the theft of a weather device that threatens to end their winter, as she and her people would melt and die if it got too warm.
At one point Thor goes into a trance as Iceman's powers grow, muttering the word "Fimbulvetr".
X-Men: In an arc on Astonishing X-Men, Iceman is corrupted by the Apocalypse Seed and allowed his powers to go out of control.
The Mighty Thor: The "Cask of Winters"/"Cask of Ancient Winters" is used to create this effect by several enemies of Asgard, especially Malekith the Accursed.
The Extremist Vector: The nuclear fallout from the detonations which destroyed civilization and all mammal life but rats on Blue Jay's home world trapped the unsurvivable remains of the planet in cold toxic darkness.
However, unlike some examples, the winter seems to be a regional thing, as some areas aren't plunged in winter.
Wolf's Rain: Implied, though it's not known how it came to that, besides that the world is After the End and, from what we can guess, the Nobles had something to do with it.
This suits her partner True Demon Lord Guy Crimson just fine, as this ensures nothing but the strongest beings can hope to survive within his territory, nearly all of which belong to the demon armies under his command.
That Time I Got Reincarnated as a Slime: The "Ice Continent" exists in a state of perpetual cold because of the presence of the True Dragon Velzard, whose passive aura keeps it frozen over at -120 degrees Celsius.
After learning about this, Takiko decides to use one of the wishes she can ask from Genbu the God save the realm when Genbu is summoned she specifically makes the wish to "bring spring back", which ultimately averts the upcoming ice age via a World-Healing Wave. The glacial era that is about to engulf and destroy the country of Hokkan comes from a prophecy, rather than anyone's evil plans.
The Earth in Fire Punch is going through a Glacial Apocalypse and it only gets colder.
If not for a couple of heating satellites, it would be completely uninhabitable.
The world of Aposimz is set on the surface of a former asteroid colony where it's always snowing.