The 22-year-old pipped first runner-up Miss Mexico, Perla Beltran Acosta, to the title while Miss South Africa, Tatum Keshwar, landed as the second runner-up.
Aldorino said she "had no words" to describe her emotions after the win at the ceremony in the South African city, reports the Telegraph.
Miss England, known as Lance Corporal Katrina Hodge, 22-year-old, praised the beauty for winning the crown.
She said, "I was so proud to represent England in Miss World in front of two billion viewers; I'm chuffed to bits for Miss Gibraltar, the winner. She is a real natural beauty who wasn't expecting to win at all."
She added, "I've enjoyed every minute of it and looking forward to my six months' reign as Miss England when I get back, as I want to use my title to promote the British Army. Well done Gibraltar!"