The Potong Pasir Single Member Constituency is a Single Member Constituency (SMC) in the central region of Singapore. It is managed by Jalan Besar Town Council. The current Member of Parliament of the constituency is People's Action Party (PAP) Sitoh Yih Pin.

The constituency's most famous MP is Mr Chiam See Tong, who currently leads the Singapore People's Party. Back when he was with the Singapore Democratic Party, he defeated the People's Action Party's candidate, Mah Bow Tan (who would later become a Cabinet Minister and MP for Tampines GRC) in the 1984 general election, as well as other candidates such as Sitoh Yih Pin and Andy Gan Lai Chiang.

Between 2001 and 2011, this seat was one of only two opposition seats in the Parliament of Singapore (the other being Hougang SMC, held by the Workers' Party's Low Thia Khiang). Since Chiam entered Parliament in 1984, this made him the longest-serving opposition MP in Singapore's history as of 2011.

The seat used to be a hotly contested seat in the general elections. In the 2001 general election, Chiam won the seat by 751 votes to Sitoh, clinching 52.4% of the votes. Chiam subsequently improved his winning margin to 55.8% in the 2006 general election.

In 2011, Chiam, as well as Low, experimented with leading a team to contest a nearby GRC (in Chiam's case, the Bishan–Toa Payoh GRC). Unlike Low and his party (who won both the GRC they contested as well as his original seat), Chiam and his party were defeated by the PAP in both constituencies. Not only were Chiam and his team defeated in Bishan–Toa Payoh, they also lost Potong Pasir to the PAP's Sitoh, who defeated Chiam's successor (and wife), Lina Loh Woon Lee on a marginal percentage of 0.72%. After that election, Mrs Lina Chiam became a Non-constituency MP (NCMP), having been the best performing loser at the polls.

In 2015, Sitoh retained his seat, this time with 66.41% of the votes, again defeating Mrs Lina Chiam. With Chiam illegible for a seat as an NCMP since she was not one of the best performing losers at that year's polls, this concluded a 31-year long streak of the Chiam family's presence in Parliament.

Following the release of the EBRC report for the 2020 General Election, Blocks 210 to 224 of Lorong 8 Toa Payoh were consolidated into the 4-member Bishan–Toa Payoh GRC while this constituency in return, took the Joo Seng and Woodleigh neighbourhoods from the neighbouring Marine Parade GRC's Geylang Serai ward, to allow further development.

In 2025, Potong Pasir may be giving away the Tannery portion and Wan Tho Avenue to Jalan Besar GRC.

This SMC was another opposition stronghold area of Singapore People's Party, Singapore Democratic Party and Singapore Democratic Alliance, Chiam See Tong but the People's Action Party managed to reclaim back the SMC in 2011. Potong Pasir SMC and Jalan Besar GRC are under the same Town Council, Jalan Besar Town Council.

People's Action Party Sitoh Yih Pin defeated Singapore People's Party Jose Raymond with a vote count of 60.67% vs 39.33%, winning a third term as the incumbent MP for Potong Pasir.

Note : Elections Department Singapore do not include rejected votes for calculation of candidate's vote share. Hence, the total of all candidates' vote share will be 100%.

General Election 1976: Potong Pasir

Party		Candidate	Votes	%	±%
	PAP	Ivan Cuthbert Baptist	9,667	74.8	8.6
	WP	Quek Doh Lam	3,252	25.2	8.6
Majority			6,415	49.6	12.3
Turnout			13,255	93.6	2.1
	PAP hold		Swing	8.6

By Election 1979: Potong Pasir

Party		Candidate	Votes	%	±%
	PAP	Howe Yoon Chong	9,056	66.9	7.9
	Independent	Chiam See Tong	4,491	33.1	N/A
Majority			4,565	33.7	15.8
Turnout			13,845	94.2	0.6
	PAP hold		Swing	7.9

General Election 1980: Potong Pasir

Party		Candidate	Votes	%	±%
	PAP	Howe Yoon Chong	5,509	59.0	7.9
	SDP	Chiam See Tong	3,821	41.0	7.9
Majority			1,688	18.0	31.6
Turnout			9,486	94.2	0.6
	PAP hold		Swing	7.9

General Election 1984: Potong Pasir

Party		Candidate	Votes	%	±%
	SDP	Chiam See Tong	10,128	60.3	19.3
	PAP	Mah Bow Tan	6,674	39.7	19.3
Majority			3,454	20.6	38.6
Turnout			17,078	95.3	1.1
	SDP gain from PAP		Swing	19.3

General Election 1988: Potong Pasir

Party		Candidate	Votes	%	±%
	SDP	Chiam See Tong	11,804	63.1	2.8
	PAP	Kenneth Chen Koon Lap	6,893	36.9	2.8
Majority			4,911	26.2	5.6
Turnout			18,697	95.4	0.1
	SDP hold		Swing	2.8

General Election 1991: Potong Pasir

Party		Candidate	Votes	%	±%
	SDP	Chiam See Tong	12,582	69.64	6.5
	PAP	Andy Gan	5,486	30.36	6.5
Majority			7,096	39.2	13.0
Turnout			18,325	95.1	0.3
	SDP hold		Swing	6.5

General Election 1997: Potong Pasir

Party		Candidate	Votes	%	±%
	SPP	Chiam See Tong	9,709	55.15	14.49
	PAP	Andy Gan	7,895	44.85	14.4
Majority			1,814	10.30	N/A
Turnout			17,884	95.1	0
	SPP gain from SDP		Swing	14.4

General Election 2001: Potong Pasir

Party		Candidate	Votes	%	±%
	SDA	Chiam See Tong	8,107	52.43	2.72
	PAP	Sitoh Yih Pin	7,356	47.57	2.8
Majority			751	4.8	5.6
Turnout			15,463	98.9	3.8
	SDA gain from SPP		Swing	2.8

General Election 2006: Potong Pasir

Party		Candidate	Votes	%	±%
	SDA	Chiam See Tong	8,245	55.82	3.39
	PAP	Sitoh Yih Pin	6,527	44.18	3.4
Majority			1,718	11.6	6.8
Turnout			14,958	94.1	4.8
	SDA hold		Swing	3.4

General Election 2011: Potong Pasir

Party		Candidate	Votes	%	±%
	PAP	Sitoh Yih Pin	7,992	50.36	6.18
	SPP	Lina Chiam	7,878	49.64	6.2
Majority			114	0.8	12.4
Turnout			16,112	93.0	1.1
	PAP gain from SDA		Swing	6.2

General Election 2015: Potong Pasir

Party		Candidate	Votes	%	±%
	PAP	Sitoh Yih Pin	10,581	66.41	16.05
	SPP	Lina Chiam	5,353	33.59	16.05
Majority			5,228	32.10	31.30
Rejected ballots			224	1.39	-
Turnout			16,158	92.82	0.18
Registered electors			17,407
	PAP hold		Swing	16.05

General Election 2020: Potong Pasir

Party		Candidate	Votes	%	±%
	PAP	Sitoh Yih Pin	11,264	60.67	5.74
	SPP	Jose Raymond	7,302	39.33	5.74
Majority			3,962	21.34
Rejected ballots			279	1.48
Turnout			18,845	95.51	2.69
Registered electors			19,731
	PAP hold		Swing	5.74

• 2020 General Election's result
• 2011 General Election's result
• 2006 General Election's result
• 2001 General Election's result
• 1984 General Election's result
• 1980 General Election's result
• 1976 General Election's result
• 1972 General Election's result
• 1968 General Election's result