The Argentinian centre-back was shown a straight red card by referee Keith Stroud for a tackle on Philippe Coutinho during stoppage-time in the 2-1 Capital One Cup defeat at Anfield.
The tackle was deemed as serious foul play and Fernandez faced a three-match ban, starting with Saturday's Barclays Premier League trip to Everton.
Swansea appealed against the decision with a written statement and video evidence and a Football Association appeals panel overturned the red card on Thursday afternoon.
A club statement said: "Swansea City can confirm that the Football Association has rescinded the red card shown to defender Federico Fernandez against Liverpool in midweek."
Swansea manager Garry Monk had expressed his disappointment at the decision to send off Fernandez, the fourth round tie standing at 1-1 with extra-time beckoning before Liverpool defender Dejan Lovren made the most of the visitors being reduced to 10 men with a 95th-minute winner.
"It clearly wasn't a sending off," said Monk, who will meet Mike Riley, the general manager of the Professional Game Match Officials Limited, on Friday to discuss decisions which he says have consistently gone against his side this season.
"Hopefully the referee will see some sense and the authorities will rescind that red card, because it wasn't a red card at all.
"It's an honest challenge
If anything, Coutinho's feet were higher than ours and actually went in over the top of our player.
"I don't quite see how the referee saw that, but hopefully he sees sense and rescinds it."
Fernandez is now free to make sixth-place Swansea's trip to Goodison Park on Saturday.
Source : PA
Source: PA