The 24-year-old Finland international striker has signed a three year contract for a fee estimated at around £3million and becomes manager Steve Bruce's first major signing of the summer.
Forssell began last season on a second season long loan deal at Blues having spent a successful full campaign at St. Andrew's the season before. However, after just a handful of appearances he returned to Chelsea in September to undergo a major knee operation and has only recently returned to first team action.
Everton appeared to be leading the race for Forssell's signature until recently but the Blues' Player of the Season 2003-04 has opted for a move back to St Andrew's.
Welcome home Mikael!