Reports have linked City with a move for 21-year-old Spurs star Alli, who was named England's Young Player of the Year for the second season running on Sunday.
But Guardiola told Sky Sports: "Mauricio Pochettino has to stay calm. Dele Alli will be his player next season. I am pretty sure about that. We don't want him.
"He is a fantastic player – (a) good, new, English footballer. He's a fighter. He's good. He's someone who attacks the box and is one of the most fantastic players I have ever seen in my life.
"But Manchester City doesn't want Dele Alli."
City host derby rivals Manchester United on Thursday hoping to preserve their grip on the fourth and final Champions League qualifying berth.
Guardiola says City must improve their home form if they are to salvage something from a season destined to end without a trophy following last Sunday's FA Cup semi-final defeat by Arsenal.
City have dropped 15 points at home this season and with four of their final six matches at home, Guardiola says their form at the Etihad will dictate which European competition they qualify for.
"We have six games left, four at the Etihad, so our qualification for the Champions League depends on our games at home," he told reporters at City's training centre.
"I have been managing for nine years and this is my first year without a trophy.
"Sometimes it has to happen and it happens now. If I extend my career a lot in the future, I am sure it will happen again, but there are a lot of big clubs in Europe without a trophy."
City's FA Cup elimination was a major disappointment for Guardiola and his players, but he is certain that they are mentally strong enough to recover quickly.
"Today, the mood is better than yesterday and tomorrow it will be better than today," he said.
"It (the Arsenal game) is over, it is past. We play to win. We were better, but we didn't win. Congratulations Arsenal."
David Silva remains a major doubt for United's visit due to the knee injury he suffered against Arsenal.
Silva was forced off during the first half after finding himself on the wrong end of a fierce challenge by Gabriel that went unpunished by referee Craig Pawson.
The Spain international has been able to train this week, but Guardiola is not optimistic about his chances of playing.
"David Silva is a real, real doubt," Guardiola said. "I don't know if he will be ready to play after what happened in the first minutes in the semi-final."
Guardiola, though, is much more hopeful that Sergio Aguero will recover in time to play, while fellow striker Gabriel Jesus could also be involved in the squad.
Aguero came off during extra time on Sunday, still suffering the effects of a knee in the back from Laurent Koscielny.
Jesus is close to full fitness, having been out of action since breaking a bone in his foot during the 2-0 win at Bournemouth on February 13.
Guardiola said: "Gabriel has no pain at all, so is ready, but after nearly three months out his condition is not optimal. Sergio is much better. Today he has been a part of the training session."
The City manager is prepared to play Aguero and Jesus together in the final games of the season, insisting that their combination can work.
Before his injury, Jesus was preferred to Aguero in the central attacking role, with the Argentina international left on the bench regularly following the Brazil striker's January move from Palmeiras.
"Yeah, they can play together," Guardiola said. "You can play two strikers or without wingers. With wingers wide, it is more complicated."