The match will be held at the Gabba on September 4, with both clubs agreeing to "strict travel arrangements and other protocols as approved by the Queensland Government".
The Bulldogs are set to continue their quarantine period in Tasmania this week before heading to Queensland on Friday.
“We are pleased to be able to confirm the Semi Final between the Brisbane Lions and the Western Bulldogs will be played at The Gabba on Saturday night,” AFL General Manager of Clubs and Broadcasting Travis Auld said via the league's statement.
“It has been an incredible start to the finals series and with 100 per cent capacity crowds returning in Queensland this weekend, we look forward to seeing members and supporters pack The Gabba for what is shaping up to be a great contest.
“On behalf of the AFL, I would like to thank each Club, players, coaches, staff and their families, umpires, AFLPA, fans, broadcast and commercial partners, venues and the Queensland and Tasmanian governments for their patience and ongoing support of the 2021 Toyota AFL Finals Series.”
2021 AFL Finals Week Two Fixture:
Saturday, September 4
First Semi Final – Brisbane Lions vs. Western Bulldogs, The Gabba, 7:20pm AEST.