Townsend will undergo a medical with a view to signing a one-year contract at The Hawthorns, just over two years after leaving the club for Suffolk.
His first Baggies spell yielded 213 appearances across six seasons between 2018 and 2024, a period that included two Championship play-off semi-finals and a runners-up finish in the 2019-20 campaign that sealed automatic promotion to the Premier League.
The 33-year-old joined Ipswich Town on a two-year deal in the summer of 2024 but managed only 10 appearances during his time there, with fitness proving a persistent obstacle throughout his stay.
His last competitive outing for the Tractor Boys came in a Premier League fixture at Chelsea in April 2025, before an anterior cruciate ligament injury in his knee last summer ruled him out for the entirety of the following campaign as Kieran McKenna's side secured an immediate return to the top flight at the first attempt.
West Brom are working to add experienced cover to their defensive options as they prepare for the new Championship season, with the club continuing to strengthen in wide areas following the departures of former captain Jed Wallace and winger Karlan Grant, who returned to his old club Charlton Athletic earlier this week.
Townsend previously served as stand-in captain during his first stint at The Hawthorns and remains well known to the club's coaching staff, having been a regular in the left-back role across his six years at the club. His versatility, having also featured at centre-back during his first spell, is understood to be viewed as a useful option by the Albion hierarchy.
Should the move go through, it would mark West Brom's fourth confirmed signing of the summer, with the club continuing to work on further additions as they look to strengthen a squad considered light in certain positions ahead of the new campaign.