The twentieth season of Australian reality television series The Block premiered on 12 August 2024 on the Nine Network. Hosts Scott Cam and Shelley Craft, Dan Reilly takes over being site foremen from Keith Schleiger as he was unable to move to Phillip Island full time, and judges Shaynna Blaze and Darren Palmer, all returning from the previous season, with Marty Fox taking over judging from Neale Whitaker.
Applications for the twentieth season of the series opened in September 2023 until 15 October 2023, looking for couples aged between 18 and 65 years old being sought by casting agents. Filming was expected to be a 12-week shoot period from late February 2024. In September 2023, the twentieth season of The Block was officially confirmed at Nine's 2024 upfronts. The location for this season was set to be in Daylesford, Victoria, but due to permit issues and complaints by local residents, Nine decided not to build in the area and started searching for a new location. In October 2023, it was reported Nine had purchased the Island Cove Villas, set over 2.5 acres, for $9.5 Million on Phillip Island. On 3 November 2023, the location was officially confirmed by Nine. In December 2023, a tall privacy wall was built around the perimeter of the location to prevent locals from entering the premises. In May 2024, foreman Keith Schleiger announced he would be drawing back his appearance to guest this season due to family commitments. On 26 June 2024, the first teaser was shown which also revealed the contestants. It was also revealed that longtime judge Neale Whitaker would not be returning to the show as a regular judge, after previously stepping back on judging duties in 2023. Marty Fox was to return as his replacement, and Whitaker would make a guest appearance.
During the fifth week of filming, Jesse & Paige decided to leave the competition based on advice from the series psychologist, and a new team took their place with four rooms already complete. Former contestants Ronnie and Georgia filled their place for one day as a prank before Maddy and Charlotte, sisters and home flippers from New South Wales, joined The Block in the following episode. They are the youngest ever duo to compete on the show.
After the reveals of the final room, front yards, Kylie and Brad decided to leave and did not return for the final challenge. However, they did return on auction day. The last challenge, the club house, had all-stars return, but since Kylie and Brad did not come back to the work site, their all-star team, Jimmy & Tam (season 16 winners), had to renovate their rooms on their own.
The Block auctions (or Block-tions) for the houses were held on Saturday, 9 November 2024, with the final episode of 2024 airing the next day on Channel Nine and 9Now at 7:00 pm (AEDT) on Sunday, 10 November 2024.