The 25-year-old was out of contract at Marseille and he will now join the Barclays Premier League club who have been looking to strengthen their forward options since Wilfried Bony was sold to Manchester City in January
The deal was confirmed on Swansea's website.
Ayew, who was on target against the United States and Germany at the 2014 World Cup in Brazil, has won over 60 caps for Ghana and had scored 52 goals in 181 games for Marseille since making his debut in 2007.
Source : PA
Source: PA