Redmond, 32, has been without a club since departing already relegated Championship side Sheffield Wednesday in January.
He has now sealed a return to professional football in Lancashire at Blackburn with seven games to go in the Championship.
Former Premier League winners Blackburn sit four points above the drop zone, and visit St Mary’s on Saturday, April 25.
✍️ We are pleased to confirm the signing of former England international Nathan Redmond, subject to EFL/FA approval.
The 32-year-old joins as a free agent to bolster the club’s attack for the @SkyBetChamp run-in.
Welcome, Nathan! 👋#Rovers 🔵⚪️ pic.twitter.com/asGhcHc644
— Blackburn Rovers (@Rovers) March 27, 2026
Redmond’s career started at Birmingham before spells with Norwich, Saints and Turkish giants Besiktas.
He earned one England cap in 2017 and played 276 games in the Premier League, the majority of those with Saints.
Redmond turned out 232 times for Saints before leaving St Mary’s to join Besiktas on a free transfer in September 2022 – the season in which they were relegated.
He scored 30 goals and notched 27 assists across a six-year stint on the south coast. He played seven times during his short spell at Wednesday this season.