He has previously played in the National Hockey League (NHL) for the Pittsburgh Penguins, Vancouver Canucks, St. Louis Blues, Vegas Golden Knights, Seattle Kraken, San Jose Sharks, and Dallas Stars.

A highly regarded prospect, Pouliot was selected with the first overall pick in the 2009 WHL Bantam Draft by the Portland Winterhawks,[2] who placed him on their protected list.

Despite being omitted from Canada's roster for the 2012 World Junior Ice Hockey Championships, Pouliot was listed in the top-ten of North American skaters by NHL Central Scouting in the mid-season rankings, though once again not as the top defenceman.

The Winterhawks again had a stellar season, ending up as the most prolific offensive team in the WHL, due in part to Pouliot's scoring prowess.

Portland swept their opening round playoff series against the Kelowna Rockets, in which Pouliot produced two assists, and defeated the Kamloops Blazers to move on to the conference finals against the Tri-City Americans, a match-up which pitted the top offensive and defensive teams in the WHL against one another.

In another four-game sweep of the Americans, Pouliot put up a 4-assist performance in Game 2, assisting on each of the Winterhawks' goals except the overtime game-winner.

[11] In their second consecutive finals appearance, the Winterhawks were matched up against the Edmonton Oil Kings, who finished the regular season with the best record in the WHL.

[18] With the departure of fellow Penguins draft pick Joe Morrow to the American Hockey League (AHL), Pouliot became the Winterhawks' star offensive defenceman and immediately rose to the challenge.

[22] In a five-game opening series win over the Everett Silvertips, Pouliot finished with nine points[23] (six coming on the power play) as well as assisting on the game-winner in the deciding match.

[24] In a second round sweep of the Spokane Chiefs, the Winterhawks scored 18 goals and allowed only 3, and Pouliot recorded a four-point night in the opening match.

[26] Despite a disappointing loss to the Halifax Mooseheads in the Memorial Cup Final, Pouliot's seven points led all defencemen for the tournament.

[36] Giving the Blues added organizational depth on the blueline, Pouliot was assigned to the San Antonio Rampage of the AHL for the majority of the 2019–20 season.

[37] On October 9, 2020, Pouliot joined his fourth NHL outfit in agreeing to a one-year, two-way contract with the Philadelphia Flyers.

On March 21, 2022, Pouliot's brief tenure with the Golden Knights ended after he was claimed off waivers by fellow expansion club, the Seattle Kraken.

[43] In the following off-season, Pouliot continued his journeyman career by agreeing to a one-year, two-way contract with the Dallas Stars for the 2023–24 season on July 4, 2023.

[44] After a lone season with the Stars, Pouliot left to sign a one-year, two-way contract with his eighth NHL club, the Tampa Bay Lightning, on July 1, 2024.