There will be no final at home for Real Betis. The team's Benito Villamarin Stadium in Seville will host the Copa del Rey final this season, but Betis won't be there after being eliminated by Valencia in the semifinals on Thursday.
Valencia won 1-0 at home to reach the Copa final for the first time in more than a decade, where it will play Barcelona on May 25.
Striker Rodrigo scored a second-half winner for Valencia, which advanced 3-2 on aggregate after a 2-2 draw at Betis three weeks ago.
"We wanted to be in this final and we were confident that we had the team to make it," Betis defender Marc Bartra said. "Unfortunately, sometimes things don't go the way you expect in football."
On Wednesday, four-time defending champion Barcelona defeated Real Madrid 3-0 to advance to its sixth straight Copa final.
Valencia, celebrating its centennial, hadn't made it to the final since it won the last of its seven Copa titles in 2008.
"We played a very complete series and deserved to advance," Rodrigo said. "It's great to be able to reach this final in such a special year for the club."
Betis needed to score after conceding twice in the first leg at home, but it was Valencia that struck first at its Mestalla Stadium when Rodrigo found the net from close range after a pass by Kevin Gameiro following a breakaway in the 56th minute.
It took a while for Rodrigo's goal to be confirmed, but a video review eventually determined there was no offside in the build-up.
Gameiro had scored the stoppage-time equalizer in the first leg, when Valencia trailed by two goals early in the second half.
Valencia and Barcelona drew both matches they played in the Spanish league this season — 1-1 at Mestalla last year and 2-2 at Camp Nou Stadium this month.
"We will face a great team, with a player who makes the difference," Rodrigo said. "But we played two very even matches against them this season, and could have actually beaten them. It's a final, in one match, so anything can happen."
Valencia was eliminated by Barcelona in last year's Copa semifinal. It also fell to the Catalan club in the last four in 2012 and 2016.
Barcelona will be trying to win an unprecedented fifth straight Copa title, and 31st overall, the most by any club.
Valencia had a dismal start to its season, winning only one of its first 13 matches in all competitions. But it has hit its stride recently, moving closer to the European spots in the Spanish league and also reaching the last 16 in the Europa League.
(With AP Inputs)