美國海軍三棲特種部隊（英文：United States Navy Sea, Air and Land Teams，縮寫SEALs），一般稱作海豹部隊，是直屬美國海軍的一支特種部隊，亦是世界知名的特種三棲部隊，主要任務包括：非常規戰爭、國內外防禦、直接行動、反恐怖主義行動、特殊偵查任務五項。要成為一個三棲特戰隊成員並不容易，甄選者必須得先通過基礎水下爆破訓練（Basic Underwater Demolition/SEAL，BUD/S）以及專業的三棲資格訓練（SEAL Qualification Training，SQT），最後才能佩帶予顯示三棲特戰隊的佩章（佩章圖示），這枚佩章已經不僅僅是代表整個三棲特戰隊，間接也成為廣為容易辨識美國特戰部隊的佩章之一。三棲特戰隊為了與支持他們的單位相吻合，成員們須穿著戰鬥服的修改版本。在三棲特戰隊參與越南戰爭時期，穿著的是類似老虎斑紋的迷彩服，當隊員們易服執行巡邏任務時，經常穿著與平民們一樣的藍色牛仔褲和珊瑚藍高筒帆布鞋。
成員雙眼視力不得低於20/20。視力可矯正至20/20，三棲特戰隊備選者須接受射屈光角膜切除術（photorefractive keratectomy，PRK）或雷射層狀角膜切除術（laser-assisted in situ keratomileusis，LASIK）以矯正視力。以上是進入BUD/s的必備條件，不過身為一個受期待的受訓者，必須遠遠超出上述的條件，以下是較具競爭性的項目：
“Loyalty to Country, Team and Teammate Serve with Honor and Integrity On and Off the Battlefield, Ready to Lead, Ready to Follow, Never Quit, Take responsibility for your actions and the actions of your teammates, Excel as Warriors through Discipline and Innovation, Train for War, Fight to Win, Defeat our Nation's Enemies, Earn your Trident everyday.”
“In times of war or uncertainty there is a special breed of warrior ready to answer our Nation's call. A common man with uncommon desire to succeed. Forged by adversity, he stands alongside America's finest special operations forces to serve his country, the American people, and protect their way of life. I am that man.”
“My Trident is a symbol of honor and heritage. Bestowed upon me by the heroes that have gone before, it embodies the trust of those I have sworn to protect. By wearing the Trident I accept the responsibility of my chosen profession and way of life. It is a privilege that I must earn every day.”
“My loyalty to Country and Team is beyond reproach. I humbly serve as a guardian to my fellow Americans always ready to defend those who are unable to defend themselves. I do not advertise the nature of my work, nor seek recognition for my actions. I voluntarily accept the inherent hazards of my profession, placing the welfare and security of others before my own.”
“I serve with honor on and off the battlefield. The ability to control my emotions and my actions, regardless of circumstance, sets me apart from other men. Uncompromising integrity is my standard. My character and honor are steadfast. My word is my bond.”
“We expect to lead and be led. In the absence of orders I will take charge, lead my teammates and accomplish the mission. I lead by example in all situations.”
“I will never quit. I persevere and thrive on adversity. My Nation expects me to be physically harder and mentally stronger than my enemies. If knocked down, I will get back up, every time. I will draw on every remaining ounce of strength to protect my teammates and to accomplish our mission. I am never out of the fight.”
“We demand discipline. We expect innovation. The lives of my teammates and the success of our mission depend on me - my technical skill, tactical proficiency, and attention to detail. My training is never complete.”
“We train for war and fight to win. I stand ready to bring the full spectrum of combat power to bear in order to achieve my mission and the goals established by my country. The execution of my duties will be swift and violent when required yet guided by the very principles that I serve to defend.”
“Brave men have fought and died building the proud tradition and feared reputation that I am bound to uphold. In the worst of conditions, the legacy of my teammates steadies my resolve and silently guides my every deed. I will not fail.“
2012年7月，位於美國維吉尼亞海灘，專門給予三棲特戰隊使用的市訓練靶場被曝光使用伊斯蘭女性頭像作為靶標，美國伊斯蘭關係委員會(Council on American–Islamic Relations)提出抗議，並且要求五角大樓撤除這類標靶。在抗議後幾小時，美國海軍宣布下令撤除這類型引發爭議的標靶圖像。
進行水中訓練三棲特戰隊
三棲特戰隊示範逮捕俘虜
三棲特戰隊於樹林中進行任務