The 30-year-old was told he would not be offered a new deal at the Ricoh Arena for next season by manager Chris Coleman, but has now signed a two-year contract with the League One club.
Seagulls boss Micky Adams worked with the central defender during his time at the helm of the Sky Blues.
"He is a leader on the pitch. The influence he will have, particularly on our youngsters, will be invaluable," said Adams.