The former Barcelona playmaker still had a year left to run on his current deal but is now tied to the south Wales club until the end of the 2012-13 season.
The Spaniard, 26, follows in the footsteps of compatriot Angel Rangel, who penned a new three-year deal at the Liberty Stadium last week.
Orlandi made 20 appearances last term as the Swans secured promotion via the play-offs, and chairman Huw Jenkins told the club website: "(Manager) Brendan (Rodgers) was keen to ensure Andrea was retained as an important member of the squad.
"He has grown into the squad over the past few years and his technical ability is well suited to the Premier League.
"We are delighted that Andrea has decided to extend his contract, and we look forward to seeing him play his part as the club looks to make an impact in the Premier League."
Jenkins also confirmed that Swansea are hopeful of confirming new deals for several other key players, including midfielder Nathan Dyer and Joe Allen as they prepare to embark on a first top flight campaign in 28 years.
"Improving and extending certain players' contracts well in advance is something we can now look into thanks to our Premier League status," he said.
"Over the last few years we have been asked by supporters why the club did not do it, but the simple explanation is we were not in a financial position to do so."
Source: PA
Source: PA