Leader of the Opposition of the Australian Capital Territory
Coat of arms of the Australian Capital Territory
Incumbent Mark Parton since 10 November 2025
Opposition
Style	The Honourable
Member of	Legislative Assembly Shadow Cabinet
Nominator	Largest non-governing party
Appointer	ACT Legislative Assembly
Inaugural holder	Trevor Kaine
Formation	11 May 1989
Deputy	Deborah Morris
Salary	$132,158 (additional) $320,956 (total)[a]

Theleader of the opposition of the Australian Capital Territory, is an official role usually occupied by the leader of the second largest party or coalition in theAustralian Capital Territory Legislative Assembly.

The title is conferred under Standing Order 5A of the ACT Legislative Assembly, that the leader of the opposition shall be the leader of the largest non-Government party, with the consent of that member. In the event of an equal number of members of the second largest party, the Assembly shall vote and elect a leader of the opposition.

Prior to 1991, the Opposition Leader was elected by a simple majority of the assembly with the government abstaining. However this was changed to be automatically the largest non-government party following the six and a half hour Duby Opposition Leadership.

The Leader of the Opposition receives a bonus salary of $132,158 on top of the $188,798 base salary already received by every member of the Legislative Assembly. Given the Opposition Leader must be an MLA, their total salary amounts to $320,956.^[1]

The office of Opposition Leader has been primarily held by the leader of theACT Branch of theLiberal Party. The party has held it consecutively through the last 24 years and 9 officeholders.

It has, however been held by theACT Branch of theLabor Party on a number of occasions. Firstly during the briefKaine government, and then again for a longer period of six years through theCarnell andHumphries governments.

The office has been held only once by a non-major party, that beingCraig Duby of theIndependents Group who stylised himself as "Coordinator of Non-Government Business". On 21 June 1991, Trevor Kaine resigned from the position to allow his party leader successorGary Humphries to take the position on. As the Liberals did not have a majority of the non-government seats, they were susceptible to a challenge by another group for the position. That challenge came from Duby who was elected and served for six and a half hours before the Labor and Liberal combined majority changed the standing orders.

No.	Portrait	Name	Election	Party	Term		Duration	Chief Minister
1		Trevor Kaine[2]	1989	Liberal	11 May 1989	5 December 1989	208 days		Rosemary Follett 1989
2		Rosemary Follett[3]	—	Labor	5 December 1989	6 June 1991	1 year, 183 days		Trevor Kaine 1989—1991
(1)		Trevor Kaine[4]	—	Liberal	6 June 1991	21 June 1991	15 days		Rosemary Follett 1991—1995
3		Craig Duby[5]	—	Independents Group	21 June 1991		6.5 hours[6]
4		Gary Humphries[7]	—	Liberal	21 June 1991	22 July 1991	31 days
(1)		Trevor Kaine[8]	1992	Liberal	22 July 1991	21 April 1993	1 year, 273 days
5		Kate Carnell[9]	1995	Liberal	21 April 1993	9 March 1995	1 year, 322 days
(2)		Rosemary Follett[10]	—	Labor	9 March 1995	5 March 1996	362 days		Kate Carnell 1995—2000
6		Andrew Whitecross[11]	—	Labor	5 March 1996	19 August 1997	1 year, 167 days
7		Wayne Berry[12]	1998	Labor	19 August 1997	20 February 1998	185 days
8		Jon Stanhope[13]	—	Labor	19 March 1998	19 October 2001	3 years, 265 days
			2001						Gary Humphries 2000—2001
(4)		Gary Humphries[14]	—	Liberal	12 November 2001	25 November 2002	1 year, 13 days		Jon Stanhope 2001—2011
9		Brendan Smyth[15]	2004	Liberal	25 November 2002	16 May 2006	3 years, 172 days
10		Bill Stefaniak[16]	—	Liberal	16 May 2006	13 December 2007	1 year, 211 days
11		Zed Seselja[17]	2008	Liberal	13 December 2007	11 January 2013	5 years, 60 days
			2012						Katy Gallagher 2011—2014
12		Jeremy Hanson[18]	—	Liberal	11 February 2013	25 October 2016	3 years, 257 days
			2016						Andrew Barr 2014—
13		Alistair Coe	2020	Liberal	25 October 2016	27 October 2020	4 years, 2 days
14		Elizabeth Lee	2024	Liberal	27 October 2020	31 October 2024	4 years, 4 days
15		Leanne Castley	—	Liberal	31 October 2024	10 November 2025	1 year, 8 days
16		Mark Parton	—	Liberal	10 November 2025	Incumbent	99 days

• Australian Capital Territory-related lists
• Lists of leaders of the opposition of Australian states and territories
• Members of the Australian Capital Territory Legislative Assembly
• Leaders of the opposition in the Australian Capital Territory

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