LibriVox - LibriVox is home to many free audiobooks. The classic works are read and recorded by volunteers so you won't have to listen to a computer generated voice. There are thousands of titles available. They are available in MP3 downloads and iTunes formats. You can also listen to them online.
Loyal Books - Loyal Books offers free public domain audiobooks. There is a top 100 list and genre categories.
Open Culture - Open Culture lists hundreds of free audiobooks from authors including Aesop, Twain, Tolstoy, Hemingway and more.
Lit2Go - Lit2Go is a free online collection of stories and poems in Mp3 (audiobook) format
StoryNory - StoryNory offers free audio stories that include fairytales, classics, myths and more.
Archive.org - The Internet Archive has a large number of free audiobooks and poetry recordings.
ThoughtAudio - ThoughtAudio offers free audio books for a selection of classic literature and philosophy titles.
Free Audio Books YouTube Channel - This YouTube channel offers thousands of audiobook recordings.
Audiobook Subscription Services
There are also many audiobook subscription services. These are free for a short time period, usually 30 days. These types of services offer the free trial period before they begin charging a monthly fee, enabling potential subscribers to try out the service.
Audible - Audible from Amazon offers a 30-day free trial. Audible claims to have the biggest audiobook selection.
Audiobooks.com - Audiobooks has a 30 day trail period. They have over 100,000 audiobooks available.
Kobo Audiobooks- Kobo offers the first audiobook free general its free trial.
Scribd - Scribd is free for 30 days. Scribd then lets users listen to unlimited audiobooks for a monthly fee. The subscription also includes ebooks and other documents.