Popsugar Living Best Of 2021 The Best Halloween Costume Ideas For 2021 We're Calling It Now! Here Are 2021's Buzziest Halloween Costume Ideas 7 August 2021 by Haley Lyndes View On One Page Photo 6 of 38 ADVERTISEMENT () Start Slideshow Share This Link Copy ← Use Arrow Keys → 6 Cassie From Promising Young Woman What to wear: Cassie in the final scene of Promising Young Woman is the perfect costume for Halloween. Wear a nurse's outfit with a colourful wig, and don't forget to look like you're up to no good. Previous Next Start Slideshow Best Of 2021Halloween Costumes For MenHalloween Costumes For WomenPop Culture Halloween CostumesHalloween CostumesHalloween