Rachel Webb said her son Tom Webb will be greatly missed by family and friends, including by his girlfriend Roxy.
The 22-year-old, from Alvaston, died in hospital after being found in St Peter's Street on Tuesday evening.
A 16-year-old boy has been charged with murder.
"I can't express how completely devastated I am," said Ms Webb.
"My son was just starting out on his life's journey.
"Tom was well known for his kind, loving, thoughtful nature, his emotional strength and great humour."
She thanked friends and family for their kind words and candle lighting.
"Thank you also to Tom's beautiful girlfriend Roxy, who filled his heart with love," she said.
The 16-year-old boy charged with murder, who cannot be named for legal reasons, is due to appear at Nottingham Crown Court on Monday.
Police are still keen to speak to anyone who was in the area on Tuesday night.
Det Ch Insp Dave Cox said there was a large group of 10-20 young people at McDonald's shortly before the incident happened.
Police are working to identify them through CCTV .
If they do not come forward, police intend to release the images to the wider public.
The mother of a young man who died after being stabbed in Derby city centre has said she is "completely devastated".