Jota's Liverpool team-mate Darwin Nunez said there were "no words of comfort for so much pain".
"I will always remember you with your smile, as a good companion on and off the field," he added.
"I send all my strength to his family, from where he is I'm sure he will always be with you, especially his wife and three children."
Liverpool legend Sir Kenny Dalglish said "football is not important at this sad time", adding: "You feel helpless, knowing there's so little we can do to ease the pain for his wife of just two weeks, his three beautiful children.
"Thinking and praying for all their loved ones after the devastating loss of both Diogo and Andre. YNWA."
Former England and Liverpool defender Jamie Carragher said he was "in a state of shock".
"I can only imagine how his team-mates feel at Liverpool and Portugal, they must be in a world of pain with his friends and family," Carragher told Sky Sports.
"It just shows us all how quickly life can change. What a summer he's had, and you get this devastating news that his family have had in the last few hours. You can't even comprehend it."
Former England and Liverpool midfielder Steven Gerrard posted on Instagram: "RIP Diogo. Condolences to his family and friends during this incredibly sad time."
Manchester United captain and Portugal team-mate Bruno Fernandes called Jota a "friend colleague and companion of a thousand battles".
He added: "It's hard to understand how can someone leave so soon.
"May you and your brother find the peace you need to watch over your loved ones who lost you too soon and suddenly. My condolences to all your family."
Jota's Portugal team-mate Ruben Neves, who is playing at the Fifa Club World Cup for Al-Hilal, said: "They say we only lose people when we forget them. I will never forget you."
Fulham striker Raul Jimenez, who played with Jota at Wolves, posted on Instagram: "It's hard to get this kind of news and I still can't believe it.
"An excellent colleague, friend and above all a great father. Thank you for everything friend, we will always remember you."
NBA legend and LA Lakers power forward LeBron James, who is a minority owner of Liverpool, wrote on X "my prayers go out to his loved ones".
Legendary tennis player Rafael Nadal described Jota's death as "sad and painful news".
"All my love, affection and support go out to his wife, children, family and friends at this difficult time," the 22-time Grand Slam champion added.
Manchester City's Jack Grealish posted he was "lost for words", while Manchester United's Portuguese defender Diogo Dalot said he was "speechless".
Former Liverpool defender Stephen Warnock told BBC Radio 5 Live: "You saw the smile on his face when he played. He was always that bubbly character, but he was also a fiery person on the pitch. He had that lovely balance.
"He was always happy to give up his time, more than gracious when he spoke to people, very respectful but also a very charismatic character. I don't think you become a fans' favourite without being that type of person."