Some 50,000 people have flooded the basilica to pay homage to the late pontiff since his body was laid out on Wednesday in an open coffin ahead of his funeral on Saturday, Vatican officials said.
Francis died aged 88 on Monday morning in his rooms at the Vatican's Santa Marta guesthouse, having only recently left hospital after five weeks being treated for double pneumonia.
"He was a wonderful pope," said Rome resident Alessandra Caccamo, as she queued outside the Vatican. "I'm going to miss him so much, because it's like I've lost a piece of me."
Francis, who was from Argentina and was the first non-European pope in 1,300 years, had an often turbulent 12-year reign in which he repeatedly clashed with Church traditionalists and championed the poor and marginalised.
On Saturday, over 170 delegations including heads of state and government including US President Donald Trump are expected in St Peter's Square for the funeral ceremony, with millions more watching on television across the globe.
Source: Reuters