British Columbia Southern Interior (formerly known as Southern Interior, Kootenay—Boundary—Okanagan and West Kootenay—Okanagan) was a federal electoral district in the province of British Columbia, Canada, that had been represented in the House of Commons of Canada from 1997 to 2015.

Regions included in the riding are the Similkameen, the southern half of the South Okanagan region, the Boundary Country, all of the West Kootenay region, the Slocan Valley, Lower (but not Upper) Arrow Lake, and including the east shore of Kootenay Lake from opposite Kaslo northwards.

Municipalities within the riding are Princeton, Keremeos, Oliver, Osoyoos, Greenwood, Grand Forks, Trail, Rossland, Warfield, Montrose, Fruitvale, Castlegar, Nelson, Salmo, Slocan, New Denver, Silverton, and Kaslo.

This riding was created in 1996 as "West Kootenay—Okanagan" from parts of Kootenay West—Revelstoke and Okanagan—Similkameen—Merritt ridings.

It consisted of:

• Kootenay Boundary Regional District;
• subdivisions A and B of Central Kootenay Regional District; and
• the eastern part of Subdivision B of Okanagan-Similkameen Regional District.

It was renamed "Kootenay—Boundary—Okanagan" in 1998.

In the 2003 redistribution, the riding was replaced by the new riding of Southern Interior, with a small part being redistributed into Kootenay—Columbia and a small part added from Okanagan—Coquihalla.

In 2004, its name was changed to "British Columbia Southern Interior".

Parliament	Years	Member		Party
West Kootenay—Okanagan Riding created from Kootenay West—Revelstoke and Okanagan—Similkameen—Merritt
36th	1997–2000		Jim Gouk	Reform
	2000–2000			Alliance
Kootenay—Boundary—Okanagan
37th	2000–2003		Jim Gouk	Alliance
	2003–2004			Conservative
Southern Interior
38th	2004–2006		Jim Gouk	Conservative
British Columbia Southern Interior
39th	2006–2008		Alex Atamanenko	New Democratic
40th	2008–2011
41st	2011–2015
Riding dissolved into South Okanagan—West Kootenay, Central Okanagan—Similkameen—Nicola and Kootenay—Columbia

2011 Canadian federal election
Party	Candidate	Votes	%	±%	Expenditures
	New Democratic	Alex Atamanenko	25,176	50.9	+3.4
	Conservative	Stephen Hill	19,276	38.9	+3.1
	Green	Bryan Hunt	3,173	6.4	-3.2
	Liberal	Shannon (Shan) Lavell	1,872	3.8	-3.1
Total valid votes/Expense limit			49,674	100.0

2008 Canadian federal election
Party	Candidate	Votes	%	±%	Expenditures
	New Democratic	Alex Atamanenko	22,693	47.5	-1.5	$66,606
	Conservative	Rob Zandee	17,122	35.9	+16.6	$76,704
	Green	Andy Morel	4,573	9.6	-1.7	$8,439
	Liberal	Brenda Jagpal	3,292	6.9	-13.3	$28,430
	Marxist–Leninist	Brian Sproule	80	0.2	-0.1	--
Total valid votes/Expense limit			47,915	100.0	$92,328
Total rejected ballots			155	0.3	-0.2
Turnout			47,915	63.89

2006 Canadian federal election
Party	Candidate	Votes	%	±%	Expenditures
	New Democratic	Alex Atamanenko	22,742	49.0	+13.9	$72,595
	Liberal	Bill Profili	9,383	20.2	+2.2	$40,534
	Conservative	Derek Zeisman	8,948	19.3	-17.3	$53,470
	Green	Scott Leyland	5,258	11.3	+3.4	$14,334
	Marxist–Leninist	Brian Sproule	123	0.3	+0.2	$0
Total valid votes			46454	100.0
Total rejected ballots			236	0.5
Turnout			46,690	66.4
	NDP gain from Conservative		Swing	+15.6

2004 Canadian federal election
Party	Candidate	Votes	%	±%	Expenditures
	Conservative	Jim Gouk	16,940	36.6	*	$55,553
	New Democratic	Alex Atamanenko	16,260	35.1	+25.3	$22,019
	Liberal	Doug Stanley	8,310	18.0	-9.4	$74,051
	Green	Scott Leyland	3,663	7.9	+1.4	$16,098
	Independent	Robert Schuster	591	1.3	*	$9,264
	Marijuana	Karine Cyr	391	0.8	*
	Canadian Action	Farlie Paynter	87	0.2	*	$454
	Marxist–Leninist	Brian Sproule	39	0.1	*
Total valid votes			46,281	100.0
Total rejected ballots			163	0.4
Turnout			46,444	60.0

2000 Canadian federal election
Party	Candidate	Votes	%	±%	Expenditures
	Alliance	Jim Gouk	19,386	46.69	-0.09	$42,724
	Liberal	Bill Barlee	11,357	27.35	+9.88	$32,709
	New Democratic	Don Scarlett	4,091	9.85	-12.04	$7,473
	Green	Andrew Shadrack	2,689	6.47	+0.42	$14,652
	Progressive Conservative	Michele Elise Duncan	2,147	5.17	-0.39	$3,532
	Marijuana	Dan Loehndorf	889	2.14	–	$978
	Canadian Action	Bev Collins	762	1.84	+0.91	$3,220
	Natural Law	Annie Holtby	191	0.46	±0	$886
Total valid votes			41,512	100.0
Total rejected ballots			238	0.57
Turnout			41,750	64.86
	Alliance hold		Swing		-4.98
Change for the Canadian Alliance is based on the Reform Party.

1997 Canadian federal election
Party	Candidate	Votes	%	Expenditures
	Reform	Jim Gouk	18,954	46.78	$45,047
	New Democratic	Kirk Duff	8,869	21.89	$40,603
	Liberal	John A. Greaves	7,078	17.47	$17,158
	Green	Andy Shadrack	2,455	6.05	$6,527
	Progressive Conservative	Blair Suffredine	2,255	5.56	$23,236
	Canadian Action	Beverly Bev Collins	377	0.93	$2,816
	Christian Heritage	Brian J. Zacharias	340	0.83	$1,372
	Natural Law	Ruth Anne Taves	187	0.46	$498
Total valid votes			40,515	100.0
Total rejected ballots			185	0.45
Turnout			40,700	66.68
This riding was created from parts of Kootenay West—Revelstoke and Okanagan—Similkameen—Merritt, both of which elected a Reform candidate in the previous election. Reform candidate Jim Gouk was the incumbent from Kootenay West—Revelstoke.

• List of Canadian federal electoral districts
• Historical federal electoral districts of Canada
• Okanagan (electoral districts)

• "British Columbia Southern Interior (Code 59026) Census Profile". 2011 census. Government of Canada - Statistics Canada. Retrieved 2011-03-06.
• Library of Parliament Riding Profile (1996-1998)
• Library of Parliament Riding Profile (1998-2003)
• Library of Parliament Riding Profile (2003-2004)
• Expenditures - 2000
• Expenditures – 1997
• Expenditures - 2004

• Website of the Parliament of Canada
• Riding map archived by Elections Canada

49°25′N 118°43′W / 49.42°N 118.72°W / 49.42; -118.72