Both players were off-contract at the end of this season, but will now remain in the Shire until at least the end of the 2024 campaign.
The injured duo - Hamlin-Uele with a pectoral muscle injury, and Williams with a dislocated shoulder - have both previously expressed their desire to stay with the Sharks.
Hamlin-Uele went to the level of stating he'd be willing to accept a pay cut if it meant he could remain with Cronulla into the future.
The 191-centimetre, 115-kilogram prop, who is 27 years of age, has played 69 NRL games, including six this year before injury. He had been a consistent starter within the Cronulla side before going down, and was in fine form.
“It was reported I was happy to stay at the Sharks and play for nothing,” Hamlin-Uele said in a club statement.
“But in all seriousness, I’m happy here at the Sharks, I think we have a squad that can really do something over the next few years and I never really wanted to play anywhere else.
“I’m pleased to have finalised the contract extension and will now fully focus on getting back on the field and to hopefully playing a part in the team’s run into the finals.”
Williams, on the other hand, was once touted as the eventual long-term replacement for champion lock Paul Gallen.
While Williams hasn't managed as much consistent football this year, he has six appearances under his belt, and a total of 75 across his career which launched with a 2018 debut.
“Injury setbacks from this year aside, I am enjoying my footy and playing alongside the group we have here at the Sharks and feel I’m continuing to improve under the coaching of Fitzy and the current staff,” Williams said.
“I’m looking forward to what the rest of this year and to making a major contribution over the next two seasons."