Sheffield Wednesday have completed a season-long loan deal for the 19-year-old Northern Ireland international, beating off competition from Bristol City and VfL Wolfsburg to land him.
Morrison made his senior Liverpool debut in last October's Carabao Cup defeat to Crystal Palace and came off the bench in the FA Cup win at Wolves in March, but the Manchester-born winger was shortlisted for the Premier League 2 Player of the Year award after contributing 15 goals and seven assists for Liverpool's under-21s last season.
He signed a new four-year contract with the club in May before making his senior international debut for Northern Ireland against Guinea in June.
"It's a massive club with great history and even better fans," Morrison told the Sheffield Wednesday website. "Everyone knows that the rebuild is now and I want to be part of it.
"It's a great squad in a competitive league but I feel like we can do really well in this league and I want to help in any way possible.
"I want to show the fans, the gaffer and everyone why the gaffer wanted to sign me and why I belong here."
Wednesday's sporting director, Simon Wilson, said the move came together unusually quickly.
"Kieran is a player with huge potential," Wilson said. "During his time with us, he will benefit from playing in front of huge crowds in a high intensity pressing team that wants to play and run forward, just like he is being asked at Liverpool.
"Equally, we hope to get the value of his quality in his time with us and send him back a better player and a better person. It was the shortest player call we have ever had – Kieran's enthusiasm for coming here was extremely strong and he cannot wait to get started."
Morrison, who was relegated with Wednesday from the Championship last season, is available for Thursday's League One game at home to Bradford City.
While one winger heads out on loan, Liverpool are simultaneously trying to bring a more experienced option in. The club have had a £50m bid rejected by Brighton for Yankuba Minteh, with the Gambia international having scored 10 goals and provided nine assists in 73 appearances for the Seagulls since his £30m move from Newcastle in 2024. Minteh is currently recovering from a leg injury sustained in a pre-season friendly against Roma.
Filling the void left by Salah's departure remains Andoni Iraola's priority for the closing stretch of the window, and Liverpool will continue to test the market for wide options. The club signed Victor Munoz, who can play as a winger or through the middle, from Osasuna for £34m earlier in the summer.
Paris Saint-Germain's Bradley Barcola remains a target too, and the France international is understood to be open to a move to Anfield, but the two clubs remain far apart on valuation, with PSG holding out for a fee in the region of £145m against a Liverpool offer closer to £100m.