From TF2 Wiki
There are 34 achievements and 3 milestones in the Spy pack.
For tips and strategies on how to complete these achievements, refer to the Obtaining spy achievements page.
|A Cut Above
Kill an enemy Spy wielding a Revolver, using your knife.
Backstab your Steam Community friends 10 times.
Survive 30 seconds after being ignited while cloaked.
|Come In From The Cold
Get a Revenge kill with a backstab.
Kill an Engineer who is working on a sentry gun.
Backstab a disguised spy.
While using the Cloak and Dagger, kill the same enemy 3 times, all within the same area in a single life
|Die Another Way
Kill a Sniper after your backstab breaks his Razorback.
Kill 50 enemies with the Ambassador.
Backstab a Medic that is ready to deploy an ÜberCharge.
|For Your Eyes Only
Provide an enemy with a freezecam shot of you flicking a cigarette onto their corpse.
|FYI I am a Spy
Backstab a Medic who has healed you in the last 5 seconds.
|High Value Target
Backstab an enemy who is dominating 3 or more of your teammates.
Backstab the enemy that you're currently disguised as.
Kill an enemy while you're being healed by an enemy Medic.
|Is It Safe?
Backstab 50 enemies who are capturing control points.
Sap an enemy sentry gun within 3 seconds of a teammate sapping another.
|May I Cut In?
Backstab an enemy and the Medic healing him within 10 seconds of each other.
|On Her Majesty's Secret Surface
Start capping a capture point within a second of it becoming available.
Kill 15 enemies who are standing on a control point they own.
Destroy 1000 Engineer buildings with sappers.
Sap an enemy building, then backstab the Engineer who built it within 5 seconds.
Headshot 20 Snipers with the Ambassador.
|Slash and Burn
Backstab an enemy, who then switches to Pyro before they respawn.
Kill an enemy who triggered your feign death in the last 20 seconds.
|Spies Like Us
While cloaked, bump into an enemy cloaked Spy.
Backstab 1000 enemies.
|The Man From P.U.N.C.T.U.R.E.
Stab an enemy while fencing.
|The Man with the Broken Guns
Backstab an Engineer, then sap 3 of his buildings within 10 seconds.
|The Melbourne Supremacy
Dominate a Sniper.
Backstab 3 Snipers in a single life.
Stab an enemy to death while under the influence of Jarate.
|Who's Your Daddy?
Headshot 3 Scouts with the Ambassador.
|You Only Shiv Thrice
Backstab 3 enemies within 10 seconds.
Obtain 5 of the Spy achievements.
Obtain 11 of the Spy achievements
Reward: Cloak and Dagger
Obtain 17 of the Spy achievements
Reward: Dead Ringer