Medical student Sylwia Rajchel slipped while taking a self-portrait on the ledge of the Puente de Triana bridge, media reports said.
She fell 15 feet onto the concrete footings of the structure and succumbed to her injuries.
"This was a tragic accident and we are looking to make that stretch of boulevard along the river safer," a city spokesman was quoted as saying by the Central European News.
According to Rajchel's mother, "it is hard to believe what has happened".
"It breaks my heart. I feel this is a nightmare that is not happening," she was quoted as saying.
Built in the 19th century, the Triana bridge on the Guadalquivir river is a popular spot among tourists.