All the best celebrity Halloween costumes of 2019: Gabrielle Union, Kylie Jenner and more!

Happy Halloween!

As has been customary for the past several years, Halloween celebrations have spilled out into the days -- and even weeks -- before the spookiest holiday of the year, making for an overwhelming amount of celebrity costume snaps being posted to Instagram.

Highlights this year included Ashely Graham as Jessica Rabbit, Cardi B as Poison Ivy, Kevin Hart as "The Rock," Normani as Cher and Naomi Campbell, Jessica Biel as her husband, Justin Timberlake, and Nina Dobrev as Billie Eilish.

There were also several celebs who dressed up their kids, with Kylie Jenner putting Stormi in a purple costume that mimicked her custom purple Versace gown from this year's Met Gala and Gabrielle Union donned matching Compton Clovers cheerleading uniforms with her daughter, Kaavia James, echoing her memorable role in "Bring It On."

The Kardashian-Jenners also all rocked memorable Halloween costumes this year: Between Kim Kardashian's picture-perfect Elle Woods moment to Kylie Jenner as Ariel from the "Little Mermaid" and Khloe Kardashian dressing her daughter, True Thompson, in a slew of adorable costumes, television's first family was on top of their game this Halloween.

Other stars who have rocked notable costumes so far this year include Halsey and Evan Peters, who made their red carpet debut as a couple as Sonny and Cher, Demi Lovato, Ariana Grande, Nick Viall and Kate Beckinsale.

See the best celebrity Halloween costumes from 2019 below: