January

• 12 – Lady Antebellum performed the National Anthem at the first ever College Football Playoff National Championship Game.
• 30 – The Offspring set a record for longest time between #1 singles on the Mainstream Rock charts with Coming for You, their first since Gone Away in 1997.

February

• 1 – Idina Menzel performed the National Anthem^[1] and Katy Perry performed at the halftime show during Super Bowl XLIX on February 1, making it the most watched, highest-rated, and most tweeted per second halftime show.^[2]
• 8 – The 57th Grammy Awards, hosted by LL Cool J, took place at the Staples Center in Los Angeles. British singer Sam Smith won the most awards with four including; Record of the Year, Song of the Year, Best Pop Vocal Album, and Best New Artist. Beck's Morning Phase won Album of the Year.

March

• 4 – Shania Twain announced that she will be going on her first tour in eleven years. The Rock This Country Tour began on June 5, 2015, and is billed as her farewell tour. She also plans on releasing her first studio album in thirteen years later in the year.^[3]
• 25 – One Direction announces that Zayn Malik had left the group.
• 29 – The 2nd iHeartRadio Music Awards took place at the Shrine Auditorium in Los Angeles. Taylor Swift and Justin Timberlake were among the winners.^[4]

April

• 19 – The 50th ACM Awards were held at AT&T Stadium in Arlington, Texas, hosted by Luke Bryan and Blake Shelton.

May

• 12 – Joey Alexander released his debut jazz instrumental album, My Favorite Things, which led him to a double grammy nomination at the 58th Annual Grammy Awards. Becoming the year's youngest Grammy nominee.
• 13 – Nick Fradiani was named winner of the fifteenth season of American Idol. Clark Beckham was named winner runner-up.
• 17 – The 2015 Billboard Music Awards were held at the MGM Grand Garden Arena.^[5]
• 19 – Sawyer Fredericks was named winner of the eighth season of The Voice. Meghan Linsey was named runner-up. Joshua Davis and Koryn Hawthorne finishing third and fourth place respectively.
  • - Faith No More released their first studio album in 18 years, Sol Invictus.
• 30 - Madonna gets her record 45th number-one song on the dance charts, with the song Ghosttown, surpassing George Strait for the most number-one entries on any kind of Billboard chart.

June

• 8 – The music video for "Dark Horse" by Katy Perry reached 1 billion views on Vevo, making it the first music video by a female artist to do so and the third music video overall to do so. It was the third most-viewed YouTube video of all time, and the most-watched video by a female artist until "Blank Space" by Taylor Swift took both records a month later.^[6]
• 16 – Hilary Duff released her first album in seven years, Breathe In. Breathe Out.. It hit number 5 in the US.
• 30 – Failure released their first album in 19 years, The Heart Is a Monster.

July

• 10 – Starting on this day albums will now be released on Fridays instead of Tuesdays in America. Some reasons for the change is to help prevent illegal downloads and "In the digital world, you can't make consumers wait".^[7]
  • Veruca Salt released their first studio album in 9 years, Ghost Notes. This is also the first album to feature the band's original lineup since 1997's Eight Arms to Hold You.
• 30 – The reunited Savatage played their first show in thirteen years at Wacken Open Air in Germany, which took place from July 30 to August 1.^[8]

August

• 21 – Canadian pop star Carly Rae Jepsen released her third album, Emotion. It had universal acclaim and was included on several year-end lists from publications such as NPR, NME, Complex, and The Village Voice.
• 30 – The 2015 MTV Video Music Awards were held at the Microsoft Theater at L.A. Live in Los Angeles. Taylor Swift was the big winner of the night with four awards, including Video of the Year for "Bad Blood".

September

• 11 – Slayer released their first album in six years, Repentless. Their album was their first since the death of founding guitarist Jeff Hanneman in 2013 and subsequently proved to be the band's final album following their disbandment in 2019.
• 18–19 – The 2015 iHeartRadio Music Festival took place at the MGM Grand Garden Arena in Las Vegas.

October

• 2 – Janet Jackson releases Unbreakable her first album since 2008's Discipline to widespread critical acclaim. The album goes on to top the Billboard 200 chart.
• 4 – Van Halen concluded their 2015 North American tour, performing the final date at the Hollywood Bowl in Los Angeles. It would ultimately prove to be the band's final performance before they officially disbanded, due to Eddie Van Halen's death almost exactly five years later.
• 23 – The music video for Adele's "Hello" broke the Vevo Record for the most views within a 24-hour span with 27.7 million views, beating out the previous record held by Taylor Swift's "Bad Blood".^[9] It also broke the record for shortest time to attain 100 million Vevo views, previously held by Miley Cyrus' "Wrecking Ball".^[10] In 2017, Swift took back the record with 43.2 million views with the music video for Look What You Made Me Do.^[11]

November

• 2 – Adele's comeback single "Hello" became the first song with over a million digital sales in a week.^[12]
• 7 – the 49th Country Music Association Awards was held at the Bridgestone Arena in Nashville.^[13] Brad Paisley and Carrie Underwood hosted for the eighth year in a row.
• 9 – Chester Bennington amicably departs from Stone Temple Pilots as lead singer to focus more on Linkin Park.
• 13 - Justin Bieber released his fourth album, Purpose (Justin Bieber album) making his sixth album to debut at number 1 on the Billboard 200 chart. Every song on this album has hit the US Billboard Hot 100 Chart. It was supported by four singles: "What Do You Mean?", "Sorry", "Love Yourself", and "Company". The former three singles all reached number one on the Canadian Hot 100, US Billboard Hot 100 and the UK Singles Chart. The album was among the best-selling albums of both 2015 and 2016.
• 22 – The 2015 American Music Awards was held at the Microsoft Theatre in Los Angeles.
• 28 – Billboard reported Adele's 25 sold 3.38 million in pure album sales in its first week of release, according to Nielsen Music. That's the largest single sales week for an album since Nielsen began tracking point-of-sale music purchases in 1991, surpassing the previous single-week sales record, held by NSYNC's No Strings Attached (2.42 million sold in the week ending March 26, 2000).^[14]

December

• 3 – Former Stone Temple Pilots & Velvet Revolver singer Scott Weiland is found dead on his tour bus in Bloomington, Minnesota at the age of 48 while on tour with his band, the Wildabouts.
• 8 – Nominations for the 58th Annual Grammy Awards were announced, with Kendrick Lamar leading the list.^[15]
• 15 – Jordan Smith was named winner of the ninth season of The Voice. Emily Ann Roberts was named runner-up. Barrett Baber and Jeffery Austin finishing third and fourth place respectively.

January

February

March

April

May

June

July

August

September

October

November

December

Billboard Hot 100 No. 1 Songs

• "Bad Blood" – Taylor Swift feat. Kendrick Lamar (1 week)
• "Blank Space" – Taylor Swift (5 weeks in 2014, 2 weeks in 2015)
• "Can't Feel My Face" – The Weeknd (3 weeks)
• "Cheerleader" – OMI (6 weeks)
• "Hello" – Adele (7 weeks)
• "The Hills" – The Weeknd (6 weeks)
• "See You Again" – Wiz Khalifa feat. Charlie Puth (12 weeks)
• "Uptown Funk" – Mark Ronson feat. Bruno Mars (14 weeks)
• "What Do You Mean?" – Justin Bieber (1 week)

Billboard Hot 100 Top 20 Hits

All songs that reached the Top 20 on the Billboard Hot 100 chart during the year, complete with peak chart placement.