Bryant, 41, died on Sunday when a helicopter he was riding in crashed and burst into flames in thick fog, killing all nine people on board including his teenage daughter Gianna. Kobe was travelling with his 13-year-old daughter and seven others when the helicopter slammed into a rugged hillside in Calabasas, California.
Barcelona forward Lionel Messi posted a picture of Bryant in his Los Angeles Lakers jersey on Instagram along and wrote: "I have no words...all my love for Kobe's family and friends. It was a pleasure to meet you and share good times together. You were a genius like few others."
Juventus forward Cristiano Ronaldo also posted a picture of Bryant and said: "So sad to hear the heartbreaking news of the deaths of Kobe and his daughter Gianna. Kobe was a true legend and inspiration to so many. Sending my condolences to his family and friends and the families of all who lost their lives in the crash. RIP Legend."
Tennis star Novak Djokovic took to Twitter and wrote: "My heart truly mourns over the news today. Kobe was a great mentor and friend to me. You and your daughter will live forever in our hearts. There are not enough words to express my deepest sympathies to the Bryants and every family suffering from this tragedy. RIP my friend."
World No. 1 Rafael Nadal tweeted: "I woke up this morning with the horrible news of the tragic death of one of the greatest sportsmen in the world. Kobe Bryant, his daughter Gianna and other passengers. My condolences to his wife and families. I am in shock."
"I loved Kobe - he was like a little brother to me. We used to talk often, and I will miss those conversations very much," six-time NBA champion Michael Jordan was quoted as saying by BBC Sport.
"He was a fierce competitor, one of the greats of the game and a creative force. Kobe was also an amazing dad who loved his family deeply - and took great pride in his daughter's love for the game of basketball," he added.
Bryant finished his playing career as the Lakers' all-time leading points scorer, and is fourth on the NBA's all-time list with 33,643 points. He won gold for the US at the 2008 and 2012 Olympics.
Bryant also has an Academy Award to his name for his animated short film "Dear Basketball" in 2018.
( With inputs from IANS )