Big Semi Ajayi has joined Albion from Rotherham United for an undisclosed fee.
The giant 6ft 5in defensive rock has signed a four-year-contract at The Hawthorns and becomes Albion's second permenant summer signing.
The 25-year-old played 51 times for relegated Rotherham last season scoring 8 times.
Ajayi started his career at Charlton before transferring to Arsenal for £450,000 in 2013. He never made an appearance at The Emirates and switched to Cardiff in 2015. After loan spells at AFC Wimbledon, Crewe and Rotherham, he transferred to the Miller in 2017.
In total, Ajayi made 91 appearances for Rotherham, scoring 13 times.