The 23-year-old Spaniard has made 48 appearances for the Swans since joining from Espanyol in 2013, but has started just one Barclays Premier League game this campaign.
Swansea announced the news on their Twitter account, saying: "Swans defender @JordiAmat5 has signed a new one-year contract extension at the Liberty Stadium."
Meanwhile, Swansea forward Kenji Gorre has returned early from his loan spell at Eredivisie side Den Haag.
The 21-year-old made just five appearances after joining on an intended season-long in July.
Source: PA