Leighton Warren Smith Jr. USN (20 August 1939 – 28 November 2023) was a former United States Navy admiral. In 1994, he became the Commander in Chief of United States Naval Forces Europe and Allied Forces Southern Europe, holding the commands during the height of the Yugoslav wars. He commanded the NATO enacted no-fly zone (Operation Deny Flight) over Bosnia and the later bombing campaign against Republika Srpska (Operation Deliberate Force) in 1995. The same year he additionally took on command of the NATO-led Implementation Force (IFOR) in Bosnia with the objective of overseeing the peace agreement. He held all three positions until his retirement in 1996.

Smith was born in Mobile, Alabama, on August 20, 1939, and graduated from the United States Naval Academy with the Class of 1962. He received his wings in January 1964.

As a naval aviator, Smith flew carrier-based A-4 Skyhawk and A-7 Corsair II light attack jet aircraft during multiple deployments to the Mediterranean, North Atlantic, Western Pacific and Indian Oceans. These included three cruises in waters off North Vietnam where he flew over 280 combat missions, primarily in the A-7 Corsair II. Smith held command at sea in the aviation community at squadron and wing levels as well as major commands that included a deep draft vessel, the USS Kalamazoo (AOR-6), before taking command of the aircraft carrier USS America (CV-66) and subsequent command of Carrier Group 6 in 1986 as a flag officer. He has logged over 4,200 flying hours and accumulated over 1000 carrier arrested landings.

Smith's early flag officer tours were Director for Operations, United States European Command (1989–1991) and Deputy Chief of Naval Operations for Plans, Policy and Operations (1991–1994). Appointed to four-star rank in April 1994, he became Commander in Chief, United States Naval Forces Europe and concurrent NATO Commander in Chief Allied Forces Southern Europe (1994–1996). In December 1995, he assumed, concurrently, command of the NATO-led Implementation Force (IFOR) in Bosnia, a position he held until August 1996.

Smith's IFOR command in Bosnia was criticized by Richard Holbrooke for his refusal to use his authority to also perform nonmilitary implementation tasks, including arresting indicted war criminals:

Based on Shalikashvili's statement at White House meetings, Christopher and I had assumed that the IFOR commander would use his authority to do substantially more than he was obligated to do. The meeting with Smith shattered that hope. Smith and his British deputy, General Michael Walker, made clear that they intended to take a minimalist approach to all aspects of implementation other than force protection. Smith signaled this in his first extensive public statement to the Bosnian people, during a live call-in program on Pale Television — an odd choice for his first local media appearance. During the program, he answered a question in a manner that dangerously narrowed his own authority. He later told Newsweek about it with a curious pride.

One of the questions I was asked was, "Admiral, is it true that IFOR is going to arrest Serbs in the Serb suburbs of Sarajevo?" I said, "Absolutely not, I don't have the authority to arrest anybody."

This was an inaccurate way to describe IFOR's mandate. It was true IFOR was not supposed to make routine arrests of ordinary citizens. But IFOR had the authority to arrest indicted war criminals, and could also detain anyone who posed a threat to its forces. Knowing what the question meant, Smith had sent an unfortunate signal of reassurance to Karadžić – over his own network.