"December, 1963 (Oh, What a Night)" is a song originally performed by the Four Seasons, written by original Four Seasons keyboard player Bob Gaudio and his future wife Judy Parker, produced by Gaudio, and included on the group's album Who Loves You (1975).

The song features drummer Gerry Polci on lead vocals, with Frankie Valli, the group's usual lead vocalist, singing the bridge sections and backing vocals and bass player Don Ciccone singing the falsetto part.

According to the co-writer and longtime group member Bob Gaudio, the song's lyrics were originally set in 1933 with the title "December 5th, 1933," and celebrated the repeal of Prohibition,^[6] but after the band revolted against what Gaudio would admit was a "silly" lyric being paired with an instrumental groove they knew would be a hit,^[7] Parker, who had not written a song lyric before by that point, wrote a new set of lyrics. By Gaudio's account, the song was a recollection of his and Parker's first meeting.^[8] In real life, Parker and Gaudio had not met until 1973, when both were working as producers for Motown Records.^[9] Parker indicated that the lyrics had a more hypothetical origin, as she imagined what a man would react to his first time, while at the same time trying to maintain a degree of innocence upon which the Four Seasons had built their brand.^[7]

The idea of having Polci and Ciccone sing lead vocals instead of Valli came from Warner Bros., who were impressed when they had received a demo of their previous single "Who Loves You" with Ciccone on lead vocals, reasoned that new lead vocalists would help differentiate The Four Seasons from the solo records Valli was cutting for Private Stock Records, and briefly appointed Ciccone as the band's new lead singer. Though Valli was angered by the suggestion, the album ultimately relied upon Polci and Ciccone as lead vocalists for the rest of the songs on the album.^[10]

The single was released in December 1975 and hit number one on the UK Singles Chart on February 21, 1976.^[11] It repeated the feat on the US Billboard Hot 100 on March 13, 1976, remaining in the top spot for three weeks and one week on Cash Box. Billboard ranked it as the No. 4 song for 1976. On April 10 the same year, it topped the RPM National Top Singles Chart in Canada.^[12] It was the final Four Seasons' song to reach number one, although Valli would have one final chart-topper as a solo act in 1978 with the theme song to the film Grease.

Billboard said that it has "the flavor and fun of '60s rock with a disco feel," and praised the production and the lead and harmony vocals as well."^[2] Cash Box said it has "one of the sweetest melody lines you'll have heard throughout 1975" and that the song is "easy enough to sing along to, combined with an unforgettable bass line."^[13] Record World called it a "disco flavored item in [the Four Seasons'] timeless harmony mold."^[3]

In 1988, Dutch DJ and producer Ben Liebrand remixed the song and re-released it as a single.^[14][15] In 1993, Curb Records, who released the original version of the song, picked up the 1988 remix and released it to the U.S. market. The 1993 re-release spent 27 weeks on the Hot 100 (matching the chart life of the original 1975 single). The peak position of the remix version was #14. Adding together the two 27-week chart runs for the 1975 original single and the remixed version (for a combined total of 54 weeks, two more weeks than a full year) gave the song the longest tenure ever on the Billboard Hot 100 music chart up to that time.^[16] This remixed version has a duration of five minutes. It also became the Four Seasons' sole charting song on the Mainstream Top 40 chart, hitting a peak of #6.

A music video was produced to accompany the original 1975 release. It featured the band performing on a stage along with scenes of a 50s/early 60s diner where they were all together with young women dressed in period outfits and drinking ice cream sodas.

• Gerry Polci – drums, lead vocals (verses)
• Frankie Valli – backing vocals, lead vocals (first bridge)
• Don Ciccone – backing vocals, bass, lead vocals (second bridge)
• John Paiva – electric guitar
• Lee Shapiro – keyboards, synthesizers, horn and string arrangements
• Bob Gaudio – keyboards, producer

British pop-dance act Clock released a dance cover of "Oh What a Night" in August 1996. It peaked at number 13 in both Ireland and in the UK; in the latter country, it stayed at its peak for four nonconsecutive weeks.

The French singer Claude François also recorded a version of this song called "Cette année-là".^[63][64] The song is featured in the French jukebox musical Belles belles belles based on the works of Claude François, as well as in Jersey Boys, in which the song is inserted into the story's timeline in 1963 (and credits Nick Massi with setting Gaudio up with the here-unnamed Parker at a Christmas party).^[65]