The 25-year-old midfielder signed a four-year deal with the Baggies, becoming the third arrival at the Hawthorns this summer after the capture of Kenneth Zohor and Filip Krovinovic.
“I got a whisper towards the end of last season that Albion were watching me although I didn’t hear any more,” Ajayi told club website.
The club also announced his arrival with a Twitter post saying: “Our new No.6!“
— West Bromwich Albion (@WBA) July 20, 2019
Read also: Mikel Obi Retires From The Super Eagles