| Date/Season | Transaction |
|---|
| 7/17/2021 | Toronto Maple Leafs send Niklas Hjalmarsson to the Columbus Blue Jackets for DAL 2027 Rnd 2, $1,000,000 |
| 10/10/2018 | Nashville Predators send Drew Stafford, Jonas Holos, Marcel Goc, Robert Hagg, TB 2023 Rnd 2 to the San Jose Sharks for Niklas Hjalmarsson (rental) |
| 4/4/2018 | Vancouver Canucks send Niklas Hjalmarsson, VAN 2023 Rnd 1 to the San Jose Sharks for Matt Moulson, Philip McRae, Stu Bickel |
| 8/28/2017 | San Jose Sharks send Brandon McMillan, Niklas Hjalmarsson to the Vancouver Canucks for Nick Leddy, Ty Rattie, VAN 2025 Rnd 2 |
| 3/4/2017 | San Jose Sharks send Jeff Carter, Oliver Ekman-Larsson to the Minnesota Wild for Jonathan Toews, Niklas Hjalmarsson |
| 7/20/2015 | Minnesota Wild send NYR 2020 Rnd 2, MIN 2024 Rnd 1 to the Florida Panthers for Niklas Hjalmarsson |
| 11/11/2014 | Florida Panthers send Slater Koekkoek, FLA 2020 Rnd 2, $1,000,000 to the Buffalo Sabres for Niklas Hjalmarsson |
| 4/2/2012 | Pittsburgh Penguins send Niklas Hjalmarsson to the Buffalo Sabres for Alexandre Burrows |
| 2/16/2012 | Philadelphia Flyers send Niklas Hjalmarsson to the Pittsburgh Penguins for John Carlson |
| 10/18/2011 | Philadelphia Flyers send Joni Pitkanen, Matt Ellison to the Anaheim Ducks for Evgeni Isakov, Niklas Hjalmarsson |
| 8/3/2011 | Los Angeles Kings send Anton Gustafsson, Niklas Hjalmarsson, LA 2015 Rnd 2 to the Anaheim Ducks for Corey Locke, Dustin Kohn, Emanuel Peter, Patrick Jarrett, Taylor Ellington |
| 1/20/2010 | Pittsburgh Penguins send Niklas Hjalmarsson, $3,000,000 to the Los Angeles Kings for Colin White, LA 2013 Rnd 1 |
| 2008 | Drafted in the 2nd round, 57th overall by Toronto |
