On 5 July 2012, Nesta signed a contract with the Montreal Impact of Major League Soccer (MLS).
He signed an 18-month contract on a free transfer.
The club also stated he would not be signed as a designated player.
Nesta made his Impact debut against Lyon in a friendly match on 24 July.
He made his competitive debut three days later, in a 3–1 home win over the New York Red Bulls.
In 2013, Nesta won his first and only title with Montreal Impact: the Canadian Championship.

On 20 October 2013, Nesta announced that he would be retiring at the conclusion of the 2013 MLS Cup Playoffs after playing parts of two seasons with the Impact.
On 5 July 2012, Nesta signed a contract with the Montreal Impact of Major League Soccer (MLS). He signed an 18-month contract on a free transfer. The club also stated he would not be signed as a designated player. Nesta made his Impact debut against Lyon in a friendly match on 24 July. He made his competitive debut three days later, in a 3–1 home win over the New York Red Bulls. In 2013, Nesta won his first and only title with Montreal Impact: the Canadian Championship.
On 20 October 2013, Nesta announced that he would be retiring at the conclusion of the 2013 MLS Cup Playoffs after playing parts of two seasons with the Impact.
Alessandro Nesta