Gulli was created as a result of a partnership between a kids-television pioneer Lagardère Active and the public service France Télévisions. The former is known due to its children's channel, Canal J, while the latter has a long history investing in kids programming through its youth-oriented division on its generalist networks.
The channel was launched on 18 November 2005 on the digital terrestrial television platform in France. On 1 July 2015, Gulli launched its own HD simulcast feed on the Astra 1 satellite as part of Canalsat's complete transition to HD. On 5 April 2016, its HD feed was launched on DTT.
In 2011, the first Gulli indoor playground opened. Developed since 2009 and operated by La Boîte aux Enfants, the number of Gulli Parcs rose to 15 in October 2024.
On 23 December 2013, a deal was reached between Lagardère and France Télévisions to purchase the latter's shares in Gulli. Until then, the two groups were bound by a shareholders' agreement with a non-competition clause, which made it impossible for France Télévisions to create a public youth channel, as the Minister of Culture Aurélie Filippetti had hoped. By exiting Gulli, France Télévisions was able to create its own children's channel on France 4. As part of the negotiations for the purchase of the public service's 34% stake in Gulli, the total volume of advertising was capped in the children's programming slots on France 4 during 3 years so as not to compete in advertising with Gulli. The deal was finalised on 29 October 2014 with the transfer of 34% of France Télévisions's shares to Lagardère for €25 million.
La Grande enquête des marques préférées des familles 2018 designated Gulli as the favorite channel for parents regarding programming aimed at kids. CSA revealed in its annual reports that Gulli was one of the three national private free-to-air channels that, in 2016, was seen as profitable, behind TF1 and M6. Most private channels, however, were in the red, largely due to the growth in offer in 2012.
In 2019, Lagardère Active sold its television division to Groupe M6 in a €215 million deal, effective from 2 September.
On 3 January 2022, the new time-slot brand Gulli Prime was launched for evenings, targeting all family with a focus on adults. It was a move to revitalize Gulli despite its declining audience due to the lowering consumption of linear TV among children, to consolidate its value as the channel was considered to be sold as part of the planned merger of Groupe M6 with Groupe TF1 initiated in September 2021. As Gulli is the only consistently profitable digital channel, M6 was hoping to sell it at a good price along with Tiji and Canal J. In February, it was decided not to sell Gulli but 6ter (along with TFX), and the sale was even signed in April to Altice Média in the event of the merger being completed, which was cancelled in September due to the concessions demanded by the Competition Authority, in particular the sale of the TF1 or M6 channel. Bertelsmann then considered selling Groupe M6 for a few weeks but the timing was too tight before M6's frequency renewal.