He was joined by Stobart Group CEO, Andrew Tinkler and the gateway's operations director David Lister, to unveil a commemorative plaque marking the successful completion of the final phase of the airport’s six-year, €145 million redevelopment.
McLoughlin said: “I am very pleased to have the opportunity to see the redevelopment at London Southend Airport first hand.
"The growth the airport is seeing is fantastic news for the regional economy and passengers alike.
"This new terminal extension means better facilities for travellers and a boost for the UK’s transport infrastructure.”
London Southend Airport is Europe’s fastest growing airport, with a 57.1% rise in passenger numbers in 2013 (Airline Network News and Analysis).
It was also recently recognised as the Best Airport in Britain in Which? airport passenger survey.
Lister enthused: “It is great to have the last phase of airport regeneration officially open.
"At London Southend we pride ourselves in our simply easier experience with short walking distances, friendly staff and targets of less than four-minutes waiting time for security and 15 minutes from plane to train for passengers with hand luggage only.
"We are convinced it is those high standards of service that are responsible for London Southend becoming so popular over the past 12 months, and have extended the terminal to ensure that standards are not compromised as passenger numbers grow over time."