"Problem" is a song by American singer-songwriter Ariana Grande, featuring Australian rapper Iggy Azalea. It was released by Republic Records on April 28, 2014 as the lead single from Grande's second studio album, My Everything (2014). It was written by both alongside Ilya Salmanzadeh, Max Martin, and Savan Kotecha, being produced by the former two with Shellback, with Peter Carlsson serving as a vocal producer. "Problem" is an uptempo dance-pop and R&B song with influences of funk music, which comprises a melody based on drums, saxophone loops, and trumpets. The chorus features uncredited background vocals from American hip-hop artist Big Sean. Lyrically, Grande has stated that the song is about "the feeling of being absolutely terrified to re-approach a relationship that's gone sour – but you want to more than anything."

The song debuted at number three on the Billboard Hot 100 and sold 438,000 copies in its first week, earning Grande her biggest digital song sales week ever. The song later peaked at number two, becoming Grande's highest-charting single and Azalea's second-highest after "Fancy", which blocked "Problem" from the top spot. The song remained in the top ten of the Hot 100 for sixteen weeks and topped the US Mainstream Top 40 and Rhythmic charts. Internationally, the single debuted at the top of the charts in Ireland, New Zealand, and the United Kingdom, while peaking within the top ten of the charts in most other territories, including Australia, Canada, Mexico, Sweden, Denmark, and Greece. "Problem" became the first song to top the UK Singles Chart based on both sales and streaming.

To promote the song, Grande performed it first at the 2014 Radio Disney Music Awards, followed by the 2014 iHeartRadio Music Awards, on The Ellen DeGeneres Show and at the 2014 Billboard Music Awards. The song's accompanying music video was directed by Nev Todorovic and premiered on Vevo on May 30, 2014. It won "Best Pop Video" at the 2014 MTV Video Music Awards and has been viewed more than 1.4 billion times on YouTube as of January 2025. The song itself won "Best Song" at the 2014 MTV Europe Music Awards. As of 2024, the single has sold 3.7 million copies in the US and has been certified octuple platinum by the Recording Industry Association of America (RIAA). It ultimately reached combined sales and track-equivalent streams of 9 million units worldwide, becoming one of the best-selling singles ever.

Following the release of Grande's debut studio album Yours Truly in September 2013, which was met with critical acclaim, Grande announced in October 2013 that she had already begun writing and working on her second studio album with previous producers from her debut album, including Harmony Samuels, Babyface, The Rascals and Tommy Brown. Grande was initially aiming at releasing the album around February 2014. In January 2014, recording sessions for the album officially began and Grande confirmed she was working with new producers Ryan Tedder, Savan Kotecha, Benny Blanco and Max Martin. It was announced on March 3, 2014, that Grande would be featured on the fifth single from Chris Brown's upcoming sixth studio album X titled "Don't Be Gone Too Long". The single was originally set for release on March 25, 2014, but it was postponed due to Brown being sent to jail awaiting trial on assault charges. Grande announced the song's delay on March 17, 2014, via Twitter, stating "My loves... so obviously some things have changed recently... So we have to delay the dbgtl countdown, some things are out of our control". That same night she held a live stream to make up for the single's delay, where she previewed four new songs from her second album. Two days later, Grande revealed that due to the song's delay, she would be releasing the first single from her upcoming sophomore studio album earlier instead.

"I fell in love with Iggy when I saw this video of her performing 'Work' live, and I just thought she was so original and I loved the way she pronounced her words... I thought we would make the perfect girl-power duo for 'Problem', so I'm very grateful that she did it with me."

Grande and Azalea had originally planned for Azalea to appear on Grande's debut album in September 2013, however, it never panned out. Once Grande began working on "Problem" she thought Azalea would be the perfect fit for the track to create "the perfect girl-power duo" for the song. Azalea agreed to appear on the song and went in with producer Max Martin to write her own verse before recording it for the song. The line "one less problem without you" was inspired by an article from Cosmopolitan. Big Sean, who is featured in Grande's previous single "Right There", also appears on the song uncredited as a background vocalist in which he provides the whisper-like vocals of the chorus although he is not a featured artist. Initially while recording songs for the album, after Grande had recorded "Problem" she "fell out of love" with the song and didn't want it to appear on her second album. However, following an album listening session with her management and record label, when "Problem" came on Grande said "What the hell is wrong with me? Holy shit!", realizing her love for the song and decided to keep it for the album. Lyrically, the song is about "the feeling of being absolutely terrified to re-approach a relationship that's gone sour – but you want to more than anything."

After recording multiple songs for the album, Grande stated that she had chosen the first single from her album. On April 15, 2014, it was officially announced that "Problem" would be the title of the lead single from the album. Grande later hinted that Australian rapper Iggy Azalea would accompany her on the track. She created online buzz in the weeks leading up to her single's release through social media, first released promotional images from the single's photo shoot all throughout March 2014. On April 10, 2014, Grande asked her fans to choose between two new possible images to be used for the single's artwork release. After the votes were tallied, she revealed the winning cover artwork through her Instagram account the next day with the hashtag #10daystilproblem, and revealed that Iggy Azalea would be assisting her on the track. The winning image, the more seductive image of the pair, shows Grande leaning back in a foldout chair, dressed in a black camisole, white thigh-highs, and metal-tipped stilettos. Grande is also shown flipping through her hair while looking directly into the camera. The song was released at midnight to iTunes on April 28, 2014. The single was made available for pre-order on April 21, 2014. The single made its world radio premiere on On Air with Ryan Seacrest on April 28, 2014. A remix of the song was released on May 16, 2014, entitled the "Young California Remix" and features an additional rap verse from American rapper Problem. A Spanglish version of the song was also released featuring Colombian rapper J Balvin for the Hispanophone market, making it the second collaboration between the two artists. On August 11, a remix version by DJ Boss in Drama was released in Brazil featuring Brazilian pop singer Gretchen.

Musically, "Problem" is an uptempo dance-pop and R&B song that incorporates elements of jazz, contemporary '90s R&B, hip hop and funk which comprises the instruments like drums, saxophones and trumpets. It runs for a duration of three minutes and 14 seconds. The song was written by Grande, Azalea, Savan Kotecha, Ilya Salmanzadeh and Max Martin, and produced by the latter two along with Shellback. Musicnotes published this song in the key of G♯ minor in common time at a moderate tempo of 103 beats per minute. The melody spans the tonal range of G♯₃ to G♯₅ belt and D♯₆ in falsetto, while the music follows the chord progression of Emaj₇–F♯–B– Emaj₇–F♯–G♯m.