Alli was in sensational form for Tottenham last season, scoring 22 goals from 50 appearances.
The midfielder has been a big hit at White Hart Lane since arriving from MK Dons two years ago and is now billed as one of England's best players.
Barcelona, meanwhile, are enduring a poor transfer window with new manager Ernesto Valverde struggling to lure big-name players to the Nou Camp.
They have managed to land Nelson Semedo, re-sign Gerard Deulofeu from Everton and are nearing a deal for Spurs flop Paulinho – but Valverde's men need more.
How much are Barcelona's targets worth? Wed, June 21, 2017
Click through the gallery to reveal how much Barcelona's summer targets are worth according to CIES Football Observatory data
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Ousmane Dembele – £76.8m (€87.1m)
Barcelona are desperate to land Paris Saint-Germain star Marco Verratti, but the Italy international is likely to command a world-record fee.
And, as a result, Spanish outlet Diario Gol claim Alli is now a target.
It has previously been reported that both Lionel Messi and Neymar would love Barcelona to sign the 21-year-old.
Valverde supposedly thinks the midfielder can bring excitement back to Catalonia after their inconsistent season under Luis Enrique last time out.
Barcelona want to sign Tottenham midfielder Dele Alli
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Barcelona are struggling to land Paris Saint-Germain star Marco Verratti
The report adds that Manchester United ace Ander Herrera is also a possiblility.
But, speaking last night, the Basque midfielder ruled out leaving Old Trafford.
"There is nothing certain about Barcelona because I am very happy at United and I feel valued and focused here," he said.