COVID-19 ruined their 2020 plans but it's given the club's committee extra time to celebrate the Ron Costello Oval-based club.

One man that knows the club better than most is 68-year-old Allan 'Reg' Cody - who started with the club as an 11-year-old - and has been one of the main drivers of this event.

"At the very beginning, the club based around all local players and no real imports," said Cody, who won two first grade and three reserve grade premierships during his Sharks playing career which spanned more than 20 years.

"As we grew, it became imperative to bring in some people from out of the area, which allowed us to create plenty of interest in Shellharbour and the surrounding regions.

"This translated to success on the field and on the back of our ever-growing impact on the community, we've been able to facilitate players, both men and women, and fans - with our amazing ground and grandstand, like few others on the South Coast.

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"We've obviously spent time in Jim Beam Cup (now known as the Ron Massey Cup), NSW Cup (as a feeder club to Wayne Bennett's St George Illawarra side) and Illawarra competitions, which has provided us with the platform to allow exceptionally talented players in the area to compete at an even higher level - while also attracting players such as Wendell Sailor to the club.

"We then came full circle by rejoining Group Seven in 2014 and haven't looked back, with the club being in as strong a position, across the board, as I've seen it."

Another who has been there every step of the way since 1968 is life member Mick Galligan, who held roles such as president, vice-president, group delegate, groundsmen, fundraiser and committee member - which he still is to this day.

"It's a great town and great club - I've loved rugby league ever since my father played," said Galligan, whose wife Margaret is also a life member

"Shellharbour is one of those communities where everyone loves their footy and although it's changed a bit lately, the community's love for the sport and this club hasn't.

"That will be on full display on Saturday, which is set to be one the club's biggest ever days."

The festivities will kick-off on Friday night with the women's league tag fixture between Shellharbour and Jamberoo from 6.30pm, before the Regan Cup fixture at 7.30pm.

While all this is going on, the club will be holding a meet and greet for all past and present players, staff, committee members, coaches and volunteers in the Anna Watson Pavillon.

Then on Saturday, the two clubs will lock horns in WLT1 (9.15am), under 18s (10.15am), reserve grade (11.45am) and first grade (1.15pm) - with all Sharks associates past and present invited to form a guard of honour as the hosts run onto the field.

The significance of these two rivals facing off on this day is because in each of Shellharbour's first three grand finals in the 1930s, Jamberoo was their foe.

After the latter won the first two, the Sharks finally claimed their maiden first grade title (4-nil) in 1939 - thanks to two goals from Charlie Johnston.

"As a local junior, being able to pull on the jersey and run onto the field on Saturday will be something I'll never forget," Sharks lock Brad Chapman said.

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"There's a real buzz around the club at the moment and you can see that at training, where we've probably had our best week on the track - there's a sense that it's finally all coming together for us.

"There's no bigger test in Group Seven right now than Jamberoo, so it'll be even sweeter if we do win on Saturday, in front of all the club's old boys."

Following the action on the field, the Sharks will be holding their centenary dinner at The Shellharbour Club from 6pm.

"At the dinner, the club's team of the century will be announced," said Sharks life member and chairman of selectors for the team of the century John O'Dwyer OAM, who first became club secretary in 1958.

"It has been a task and a half trying to go back through all the years and compare the eras.

"There's a lot of players that were in the mix and there wasn't much between a lot of them - with the one criteria being they must have played first grade for the club, which eliminates a fair few juniors who left the club and went on for bigger and better things in their careers.

"I believe we've come up with the right mix and I'm excited to be there when it's revealed on Saturday."

One current player that's in the mix for the team of the century is skipper Matt Carroll, who captained the club to their most recent premiership in 2018.

While that honour would be 'incredible', the former Michael Cronin Medalist, who was a Sharks ball-boy with his cousins as a junior, is concentrating on honouring all his predecessors with a win on Saturday.

"This is my family club - my dad and uncle played here - and it's a dream to be able to play in the club's centenary season," Carroll, who this season became the competition's leading point-scorer in first grade history.

"It's amazing to pull on this special black and white jerseys and lead the boys out each week and it'll be even more special on Saturday.

"I know plenty of old faces that won premierships here who are returning just for this weekend, so there will be no better way to reward them and everyone else here on Saturday than with a win against the league-leaders.

"It'll be without a doubt one of the biggest games I've ever played in at Ron Costello Oval."

This first grade fixture, which will also mark Jye Brooker's 50th game in the top flight for Shellharbour, is one of two games that kick-off on Saturday, with the other being Gerringong's clash with the Stingrays at Michael Cronin Oval from 3pm - marking Rixon Russell's 200th first grade game for the Lions.

Then on Sunday from 3pm, Nowra-Bomaderry hosts Warilla-Lake South at Rugby Park and Albion Park-Oak Flats takes Milton-Ulladulla at Centenary Field - with Kiama having the bye.