The first leg was supposed to be played at the Estadio do Dragao in Portugal on April 7, with the second leg taking place at Stamford Bridge six days later.
UEFA has released a statement confirming the change of venue, which reads: "UEFA is able to officially confirm that the UEFA Champions League quarter-final first and second leg matches involving FC Porto and Chelsea FC, will now both be played at the Estadio Ramon Sanchez-Pizjuan in Seville.
"The dates of the matches (7 April and 13 April 2021) and the kick-off times (21:00CET) will remain the same.
"UEFA would like to thank FC Porto and Chelsea FC for their support and close cooperation, as well as the Portuguese Football Federation, The Football Association, the Royal Spanish Football Federation and Sevilla FC for their assistance and agreeing to stage the matches."
Chelsea advanced to the quarterfinal stage after beating Atletico Madrid 3-0 on aggregate while Porto eliminated Juventus on the away goals rule after a 4-4 aggregate score line.
Chelsea have already played once at the Ramon Sanchez Pizjuan this season, beating Sevilla 4-0 in the group stages.
