Montiel came through the youth system at
River Plate after signing from
Deportivo Laferrere in 2015. In February 2022, he joined
Argentinos Juniors as a free agent. He made his debut on 5 February 2023 in a win against
Racing Club. On the opening game of the
2024 Copa de la Liga Profesional on 28 January 2024, he scored against his former side River Plate. On August 14 2024, he signed for
Independiente for a fee of $1.5 million for 50% of his transfer to be paid in three installments. River Plate also received approximately 3% of the sale. Three days after signing, on 17 August 2025, he made his debut for Independiente in a 1–0 win against
Rosario Central, coming on as a second-half substitute. On December 16 2025, Santiago Montiel won the
2025 FIFA Puskás Award for a bicycle kick goal against Independiente Rivadavia. == Personal life ==