While a few teams did their best to horrify their fans by putting in some truly grizzly performances on the pitch (here's looking at you, Tottenham Hotspur), many players were simply content to don their fiendish finery and post photos of their merriment on social media.
Kylian Mbappe went all out with a zombified costume inspired by Eddie Murphy's classic 1988 movie "Coming to America."
There was a movies and TV theme for Marco Asensio, whose party guests spanned the genres with costumes inspired by "Joker," "Kill Bill," "It" and "Narcos."
Lucas Vazquez and his entire family donned a variety of Avengers costumes before heading out to the local supermarket for vital trick-or-treat supplies.
No stranger to fangs and feasting on human flesh, Luis Suarez and his brood looked absolutely frightful as they lined up for their Halloween 2021 family portrait.
With scythe in hand, Andres Iniesta got into character as the grim reaper posing alongside his corpse bride and their faithful family pet.
There was a bone-chilling variety of undead splendour on show at Pablo Sarabia's Halloween party, though first prize must surely go to the guest who brought her own coffin.
Led by the Joker and Harley Quinn, Martin Braithwaite and his family obviously meant business as they stepped out to trick-or-treat the neighbourhood.
Sevilla's Argentine players took Halloween very seriously as Erik Lamela went as a pirate, Lucas Ocampos lurked on the fringes as Edward Scissorhands and Papu Gomez spent the evening merrily jigging on the dancefloor while dressed as Chucky.
However, a special mention must be reserved for Mexican club Tigres, who went one step further by actually taking to the pitch while wearing their costumes.
Indeed, most of the starting XI raided the fancy dress box and wore masks as they lined up for their photo ahead of their game against Chivas on Saturday evening.