Djokovic will play 20-year-old Carlos Alcaraz, who said the final will be the “best moment of my life”.
On Saturday, Kate sat next to tennis great Billie Jean King and watched Czech player Marketa Vondrousova defeat Tunisian Ons Jabeur in the ladies’ singles final.
Vondrousova said she is planning matching tattoos for her and her coach to honour the grand slam win.
Pressed on the design, the tennis star told reporters: “I don’t know yet but I’ll show you guys on Instagram after.”
After the match, Kate presented both players with their trophies and was seen consoling a tearful Jabeur.
Asked in a press conference what the princess said to her, Jabeur said: “Same thing after last year – to encourage me to be strong, to come back and win a grand slam, win a Wimbledon.
“Obviously she was very nice. She didn’t know if she wants to give me a hug or not. I told her hugs are always welcome from me.
“That was a very nice moment and she’s always nice to me.”
The princess also congratulated Vondrousova on her win.
She told the Wimbledon champion: “It’s as much a mental game as it is a physical game – so really impressive and a great game to watch.
“I hope you enjoy this moment. Good luck on your recovery and down time. Lovely to see you.”
Lewis Capaldi and Emma Watson were among the famous faces watching the ladies’ singles final.
Former Wimbledon coverage presenter Sue Barker was also seen watching the game from the royal box, as was former Spider-Man star Andrew Garfield and ex-tennis champion Martina Navratilova.
British duo Alfie Hewett and Gordon Reid thrilled a packed Court One by winning their fifth Wimbledon wheelchairs doubles title on Saturday.
Hewett will now look to win his first singles title in SW19, which would complete his set of grand slam championships, on Sunday.
Britain could also have its first boys’ singles champion at Wimbledon for 61 years.
Henry Searle, 17, is yet to drop a set in the competition and knocked out the top seed in the opening round.
Some tennis fans were left disappointed after organisers announced the Wimbledon ticket queue would be closed on Saturday due to a weather warning – but better conditions are expected for the tournament’s final day.
Tom Morgan, Met Office meteorologist, told the PA news agency: “There’s a drier day in prospect for Wimbledon … but I wouldn’t entirely rule out a shower.
“The final gets under way around 2pm tomorrow so there is a chance of showers coming through tomorrow afternoon. There’s potential for an interruption.”