The 19-year-old will initially spend a month with the Mill Farm side who play in the National League North.
He could make his debut in the FA Cup against Spennymoor Town on Saturday.
Preston-born Walker was the youngest PNE player to appear in a league game when he came on as a substitute against Aston Villa in December 2018 at the age of 16.
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He had two loan spells with Carlisle United in League Two last season and hasn't been able to force his way into first-team contention at Deepdale this campaign.
AFC Fylde manager Jim Bentley told his club's official website: "I’m pleased we’ve been able to bring Ethan in to strengthen our attacking options. He is a young player with enormous potential and comes here highly regarded by all at Preston North End.
“Ethan is a talented forward player who had a successful loan spell at Carlisle last season. He’s an exciting wide player, who can go past defenders and create and score goals.
“We are all excited to both welcome him to the football club and begin working with him."
There will be a couple of familiar faces for Walker at Fylde.
His PNE team-mate Jacob Holland-Wilkinson is on loan there, while their kit man Steve Cowell worked at North End for a number of years.
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