The following is a list of all team-to-team transactions that have occurred in the National Hockey League during the 2009–10 NHL season.
Players traded or claimed off waivers after that date were not be eligible to play in the 2010 Stanley Cup playoffs.
Note: This does not include players who have re-signed with their previous team as an Unrestricted Free Agent or as a Restricted Free Agent.
The 2010 NHL entry draft was held on June 25–26, 2010.
Once an NHL player has played in a certain number of games or a set number of seasons has passed since the signing of his first NHL contract (see here), that player must be offered to all of the other NHL teams before he can be assigned to a minor league affiliate.