Animation Competitions

Deviantart

https://www.deviantart.com/digitalart/animation/popular-24-hours/

Artstation - Contests

https://www.artstation.com/contests

Inktober

https://www.mrjakeparker.com/inktober-1/

MerMay

http://mermay.com/what-is-mermay/

D&AD New Blood Contests

https://www.dandad.org/en/d-ad-new-blood-awards/

Animation Portfolio Contest

http://www.animationportfolioworkshop.com/lynn_dana_wilton/