The wide receiver signed a five-year deal with the AFC East champions just two hours after their leading receiver in 2012, Wes Welker, moved to the Denver Broncos.
The former St Louis Ram tweeted: "Blessed. Thankful. Excited to get to work. Go Pats."
Amendola, who scored three touchdowns for the Rams in 2012, will earn up to $31m (£2.05m) through his new contract.