The Avelia Horizon, called TGV M ("M" for modular) by its main customer SNCF, is a high-speed passenger train designed and produced by Alstom.

In May 2016, the Alstom-headed Speedinnov joint venture was selected as the winning bidder for the program; on 7 September 2016, SNCF and Alstom signed an agreement to design and build the new trains.

In August 2022, SNCF announced that it had exercised an option for 15 additional quad-current Avelia Horizon trainsets for international services valued at €590m.

[6] A similar trainset known as the Avelia Liberty is currently being procured by Amtrak in the United States for its Acela service along the Northeast Corridor.

In 2015, SNCF launched a program to select a supplier for a new generation of high-speed trainsets, to be designed as a joint venture with the manufacturer.

[7] The French government agency Ademe partnered with the rolling stock manufacturer Alstom to form the SpeedInnov joint venture, which submitted a bid for the SNCF's program.

The submission was for a new train that would be one part of a broader family of high-speed equipment that Alstom would pursue the sales of globally; this philosophy was a significant shift from that of all previous TGV orders, which had involving rolling stock being built specifically to suit the French market.

[12] In 2024, French start-up company Proxima ordered 12 Avelia Horizon high speed trains and 15 years of maintenance for almost 850 million euros.

It is outfitted with a modular interior that permits the operator to adapt the same basic design to suit various types of passenger experiences and market trends.

[9][10][4] The TGV M will be the first high-speed train in SNCF service to have complete digital connectivity, provisioned via an optimised onboard internet network that is reportedly capable of integrating future innovations.

[2] An intelligently-managed air conditioning system provides precision climate control for greater comfort; airflow is managed via a series of ceiling vents.