In London, One Direction's Liam Payne dressed up as Batman and Tom Daley sported a rather large skeleton costume as the pair partied at Funky Buddha. In the US, Kim Kardashian wore a blonde wig as she transformed into a mermaid for the Midori Halloween party, while Courteney Cox chose a more low-key outfit as she attended the PlayStation Epic Halloween Bash in LA.
Elswhere Glee's Darren Criss and Lea Michele attended the Rising Stars Gala, Michelle Pfeiffer hosted the 8th Annual Pink Party to benefit Cedars-Sinai Women's Cancer Programme and Jennifer Lopez looked stunning in a flowing gown as she graced the red carpet at the UNESCO charity gala.
In Dublin, Chantelle Houghton arrived at the RTE Studios to make an appearance on the The Saturday Night Show, whilst
Anna Friel left the Vaudeville Theatre in London after performing in Uncle Vanya.
See all of this weekend's pictures in our gallery below: