List of Billboard Mainstream Top 40 number-one songs of 2009

This is a list of songs which reached number one on the Billboard Mainstream Top 40 (or Pop Songs) chart in 2009.

During 2009, a total of 20 singles hit number-one on the charts.

Chart history

Issue date	Song	Artist(s)	Ref.
January 3	"Womanizer"	Britney Spears	[1]
January 10	"Live Your Life"	T.I. featuring Rihanna	[2]
January 17	"Womanizer"	Britney Spears	[3]
January 24	"Just Dance"	Lady Gaga featuring Colby O'Donis	[4]
January 31			[5]
February 7	"Single Ladies (Put a Ring on It)"	Beyoncé	[6]
February 14			[7]
February 21			[8]
February 28	"Love Story"	Taylor Swift	[9]
March 7	"Circus"	Britney Spears	[10]
March 14	"Gives You Hell"	The All-American Rejects	[11]
March 21			[12]
March 28			[13]
April 4			[14]
April 11	"Right Round"	Flo Rida featuring Ke$ha	[15]
April 18			[16]
April 25	"Poker Face"	Lady Gaga	[17]
May 2			[18]
May 9			[19]
May 16			[20]
May 23			[21]
May 30	"Boom Boom Pow"	The Black Eyed Peas	[22]
June 6			[23]
June 13			[24]
June 20			[25]
June 27			[26]
July 4			[27]
July 11			[28]
July 18	"Don't Trust Me"	3OH!3	[29]
July 25	"LoveGame"	Lady Gaga	[30]
August 1			[31]
August 8	"Waking Up in Vegas"	Katy Perry	[32]
August 15			[33]
August 22	"I Gotta Feeling"	The Black Eyed Peas	[34]
August 29			[35]
September 5			[36]
September 12			[37]
September 19			[38]
September 26			[39]
October 3			[40]
October 10	"Use Somebody"	Kings of Leon	[41]
October 17	"Down"	Jay Sean featuring Lil Wayne	[42]
October 24			[43]
October 31			[44]
November 7	"Party in the U.S.A."	Miley Cyrus	[45]
November 14	"Paparazzi"	Lady Gaga	[46]
November 21			[47]
November 28	"Whatcha Say"	Jason Derülo	[48]
December 5			[49]
December 12			[50]
December 19			[51]
December 26	"Replay"	Iyaz	[52]

See also

• 2009 in music