Imaginary Garden With Real Toads
dVerse - Poets Pub
Friday Fictioneers - write a complete story in 100 words or less based on the photo prompt
Poet's Corner - includes poetry challenges
Writing prompts - with attitude
Writer's Digest - Writing prompts mostly suitable for novels or short stories.
ThinkWritten - 365 creative writing prompts
Australian Women Writers Challenge - 2017 - Review books by Australian women.
Also, there is a Australian Women Writers Challenge group on Goodreads.
100 Word Challenge - Creative writing for young people - primary age - open to all English speaking countries.
Write 31 Days - where bloggers pick one topic and write a post on that topic every day in October.