Her breakthrough occurred with the start of her collaboration with well-known Lebanese producer Jiji Lamara, when she released her hit single "Akhasmak Ah"; created by Egyptian composer Mohamed Saad,[4] and third studio album Ya Salam (2003) in which she adopted a more sensual public image while reinventing her music.

Betfakkar Fi Eih (2008), her sixth album produced seven singles including the commercially successful Egyptian hits, "Betfakkar Fi Eih", "Min Dally Nseek" and the Lebanese single "Mashi Haddi", won Ajram's first World Music Award as world's best-selling Middle Eastern artist, the youngest Arab WMA winner to date.

[7] Throughout her career, Ajram has released twelve studio albums to date (including two dedicated for children) and numerous chart toppers such as "Yay", "Ya Tabtab", "Moegaba", "Ehsas Jdeed", "Ibn El Giran", "Fi Hagat", "Ya Kether", "Ma Tegi Hena", "Aam Betaala' Feek", "Badna Nwalee El Jaw", "Salamat", and "Aala Shanak".

She has one sister, Nadine, and one brother, Nabil Jr.[12] Ajram was only eight when she started singing with her grandmother, then carried on with successful participation in children's contests in two local television stations, TL and LBC.

At the age of 13, Ajram released her debut single "Kel Ma B'ello B Albi El Gheere" in 1996, followed by "Oulha Kelma" one year later.

In early 2002, Ajram signed a contract with renowned Lebanese producer and artist manager Jiji Lamara, four months after his splitting with Aline Khalaf.

The music video caused a controversy; reminiscent of older Arabic films, she appeared as a café manager who dances and flirts with its customers.

The tremendous success that Ah W Noss achieved, stabilized Ajram's position as an A-List star in the Arab music industry.

Nadine Labaki directed another clip that featured Ajram as a wife who sees her husband cheating on her yet she hides it in torment to save their relationship.

[21] Ajram then cooperated for the first time with prominent Lebanese director Said El Marouk, filming "Ehsas Jdeed" (A New Sentiment) which is widely considered to be the most successful song of the album.

The video was released on May 25, 2008, the day the Lebanese president General Michel Suleiman was elected ending a deadlock that lasted since November.

[35] On September 28, 2009, The Oprah Winfrey Show aired an episode titled "Fame Around the World" that talked about the most famous celebrities around the globe in brief reports.

[36] In the summer of 2010, Ajram was nominated by Coca-Cola the Middle East to sing, along with K'naan, his international hit and song for the 2010 FIFA World Cup, "Wavin' Flag".

The full music video premiered on September 6, 2010, at 8:00 pm on Arabica TV and MTV Lebanon, the same day of her seventh full-length studio album release entitled Nancy 7.

In a press conference held in Dubai on October 20, Ajram stated that she will help raise awareness of osteoporosis and bone health among women in the Middle East.

[44] After many delays, Ajram finally released her eighth full-length studio album entitled Nancy 8 on March 21, 2014, which has been highly anticipated by fans for almost four years.

[47] A month later, October 2, 2014, Huawei announced Ajram as its Middle East and North Africa Brand Ambassador at the launch of the Ascend Mate 7 smartphone in Dubai.

[49][non-primary source needed] In July 2015, Ajram was officially confirmed as a judge in the first season of the highly acclaimed TV show The Voice Kids alongside Kadim Al Sahir and Tamer Hosny.

"[53] A year after Ajram began working on her ninth studio album, the single "Maakoul El Gharam" was released on November 15, 2015, which reached the No.

1 spot on Anghami, setting a new record in 12 hours;[54][non-primary source needed] it was ultimately removed from the final track listing for her ninth studio album.

[61][non-primary source needed] The song also received commercial success, topping several Arabic music charts and radio stations for consecutive weeks.

Ajram also released a song about peace, "Risala Lil Aalam" (A Message to the World), in her first children's album Shakhbat Shakhabit as a music video, which was rumored to be presented to the UNICEF.

"[82] On October 22, 2009, the UNICEF chose Ajram to be the first female regional ambassador for the Middle East and North Africa, as was announced in a press conference held in Beirut.

In late 2009 she appeared in the UNICEF's commercial marking the 20th anniversary of the Convention on the Rights of the Child, joining other influential Middle Eastern celebrities such as Kadim Al Sahir, Saber Rebai, Mahmoud Kabil, Khaled Abol Naga, Djamel Laroussi, Caresse Bashar, Fayez Al Malki and Iranian actress Mahtab Keramati.

[84] In 2013, Ajram performed the theme song for Worth 100 Men ("Bmeet Ragel" in Arabic) – a radio fiction series produced by The Womanity Foundation, which focuses on women's education, training and development.

[85] Ajram caused controversy in 2018 when her management team arrived during the Pride festival in Gothenburg and asked for all of the rainbow flags to be removed for her to perform.

[86][87] The Lebanese singer, Hamed Sinno criticized her on a Facebook post and said that they [Mashrou' Leila] played the festival opening while all the pride flags were up.

[89] In the early hours of January 5, 2020, an armed trespasser named Mohamed Hassan Moussa broke into Ajram and her husband Fadi El Hachem's villa in Sehaileh, Keserwan District.

He used to work as a gardener for El Hachem, and had confronted his previous employer with a fake unloaded gun, asking for his unpaid salary.

[102] On February 13, 2023, a local court issued a decision clearing El Hachem from murder charges,[103] as the family of the trespasser claimed that the latter should be liable to pay compensations.