Valtteri Puustinen (born 4 June 1999) is a Finnish professional ice hockey player who is a winger for Luleå HF of the Swedish Hockey League (SHL). He made his National Hockey League debut in 2022 with the Pittsburgh Penguins.

Puustinen played as a youth within the HPK organization of the Finnish Liiga. He was drafted 203rd overall by the Pittsburgh Penguins in the 2019 NHL entry draft.

Puustinen made his Liiga debut for HPK during the 2018–19 Liiga season. He played 47 regular-season games and scored 10 goals.

In the 2020–21 season with HPK, Puustinen recorded 21 goals and 20 assists for 41 points in 51 games. His 21 goals led all HPK skaters and were tied for eighth in the league. He was one of just four skaters in Liiga to record 20 or more goals and assists.

On 6 May 2021, Puustinen was signed by the Pittsburgh Penguins to a two-year, entry-level contract. After scoring 17 goals and assists each with the Penguins' American Hockey League (AHL) affiliate, the Wilkes-Barre/Scranton Penguins, Puustinen was called up by the Penguins and played his first National Hockey League (NHL) game on 11 March 2022 against the Vegas Golden Knights. He scored his first NHL point that night, a secondary assist on Jeff Carter's goal, as the Penguins won 5–2. On 20 June 2023, he was re-signed to a one-year, two-way contract by Pittsburgh.

During the 2023–24 season, on 27 December 2023, Puustinen scored his first NHL goal in a 7–0 victory over the New York Islanders.

Puustinen was traded by the Penguins to the Colorado Avalanche during the 2025–26 season on 20 January 2026, in exchange for Ilya Solovyov. Immediately re-assigned to affiliate, the Colorado Eagles, Puustinen played out the remainder of the season in the AHL, posting 14 points through 24 regular season games and limited to 6 games in the post-season for 2 points.

As a pending restricted free agent with the Avalanche, Puustinen opted to return to Europe after securing a two-year contract with Swedish top-tier club, Luleå HF, on 10 June 2026.