Marcos Nicolás Senesi Barón (মার্কোস সেনেসি) is an Argentine professional footballer who plays as a centre-back for Premier League club Bournemouth.

Senesi made his debut for San Lorenzo on 25 September 2016 as a starter in the Argentine Primera División match against Club Atlético Patronato. On 16 September 2017, he scored his first and only goal for the club in a 1–0 win against Arsenal de Sarandí.

On 2 September 2019, Senesi signed a four-year contract with Dutch football club Feyenoord. On 10 November 2019, he scored his first goal for the club, the winning goal in a 3–2 win against RKC Waalwijk, heading in a free kick in the 85th minute.

On 8 August 2022, Senesi transferred to Premier League club Bournemouth on a four-year contract for an undisclosed fee.

Born and raised in Argentina, Senesi is of Italian descent. He was called up to both the Italy and the Argentina national teams, who were both due to face each other for the 2022 Finalissima June 2022. He chose to represent the Argentina national team, and made his debut on 5 June 2022 in a friendly match against the Estonia national team.