Felixstowe is a port town and civil parish in the East Suffolk district, in the county of Suffolk, England. The estimated population in 2017 was 24,…Felixstowe is a port town and civil parish in the East Suffolk district, in the county of Suffolk, England. The estimated population in 2017 was 24,521. The Port of Felixstowe is the largest container port in the United Kingdom. Felixstowe is approximately 72 miles northeast of London.