The band was founded in 1996 by Marc Roberge and Chris Culos, inspired in part by Roberge's older brother who plays drums for the band Foxtrot Zulu. They then recruited Richard On and Benj Gershman. The four of them graduated from Thomas Sprigg Wootton High School in Rockville, Maryland, then moved to Columbus, Ohio to attend The Ohio State University. While at Ohio State, they met Jerry DePizzo, from Youngstown, Ohio.
Without any formal marketing or advertising plans, news of their songs such as "That Was a Crazy Game of Poker", "City on Down" and "Night Shift" spread by word of mouth alone. The band played as many shows as they could, expanding from the fraternities and sororities of Ohio State to any audiences that cared to listen. This exposure paid off; their third album Risen debuted at #11 on the Billboard top internet sales chart. The following year, their fourth album Any Time Now debuted at #156 on the Billboard Top 200 list.
On October 5, 2006, a press release declared that O.A.R. had officially sold in excess of 1.2 million albums over their career. The band attributes much of its popularity to the taping and subsequent trading and downloading of their live shows. The band performs the theme song for the ABC show Extreme Makeover: Home Edition. During a two-hour special that aired on December 11, 2005, they provided a street-side concert, including a live performance of "So Much", the Extreme Makeover Home Edition theme, in front of the newly redesigned Los Angeles Free Clinic.
On January 14, 2006 O.A.R. reached a new peak of popularity by drawing roughly 18,000 fans and selling out New York City's Madison Square Garden, which earned them a review in the New York Times. Their music videos "Love and Memories" and "Lay Down" have been featured on VH1 and MTV, and they played three nights at the Gorge with the Dave Matthews Band. After having "Love And Memories" as their first radio hit, "Heard The World" was named in September 2006 as their second single off Stories of a Stranger. "Heard The World" has been Top 10 on many Maryland and D.C. radio stations, and "Love And Memories" still gets consistent air play on major radio stations.
O.A.R. performed at the 2006 Major League Baseball All Star Game in Pittsburgh during All Star Sunday, singing one of their top hits, "Love and Memories". They also performed at a rally to benefit Darfur in Central Park on September 17, 2006.
O.A.R. received a "Woodie" award from MTV in 2006; their video "Lay Down" won the Woodie for streaming video.
O.A.R. made a return trip to Madison Square Garden and performed on January 27, 2007, supported by Gomez and Matt Nathanson. This show closed out their 2007 Winter tour which started in Ohio only a few weeks earlier. On June 5, 2007 the concert was released as a DVD/Double Live CD.
O.A.R. completed a full summer tour. Their tour, called "All Sides Tour" and will began on June 15 in Manchester, TN at Bonnaroo and concluded on August 31 at the Gorge as an opening act for Dave Matthews Band. On June 16, the band played a live interactive show at DeepRockDrive in advance of the launch of their new album "All Sides".
It was officially announced by the band that their album "All Sides" is their biggest success so far. Their first radio single is called "Shattered" and it was released on June 13th. So far, it's been their biggest hit surpassing "Love And Memories".
In June 2008 the band's song "This Town" off their forthcoming album "All Sides" was used extensively by ESPN during its coverage of the 2008 NCAA Division I Baseball Tournament and College World Series.