After participating in May 2011's Operation Neptune Spear with SEAL Team Six, O'Neill was the subject of controversy for claiming to be the sole individual to kill Osama bin Laden.

[5] O'Neill claimed in 2014 that he left the military because he no longer felt "adrenaline when people are shooting, and I knew that that could lead to complacency because if I am not afraid of, that I might wind up doing something stupid thinking that I can't get hurt".

[11] According to The Intercept's interview of a former SEAL Team 6 member, when O'Neill arrived at the terrorist leader, bin Laden was already "bleeding out on the floor, possibly already dead, after being shot in the chest and leg by the lead assaulter on the raid."

"[12] As of August 2020[update], the federal government of the United States had neither confirmed nor denied O'Neill's claims,[13] though Rear Admiral Brian L. Losey and Force Master Chief Michael Magaraci did encourage all SEALs to abide by their code of silence, saying, "At Naval Special Warfare's core is the SEAL ethos […] A critical tenant [sic] of our ethos is 'I do not advertise the nature of my work, nor seek recognition for my actions.'

"[6] Of his decision to lay claim to killing bin Laden, O'Neill told CBS News that "I think it's a difficult secret to keep, […] Everyone was proud.

[14] On 14 October 2020, US president Donald Trump re-tweeted an unfounded conspiracy theory that suggested Osama bin Laden was still alive and a body double was shot instead.

"[16] That same month, CNN broadcast an interview with retired admiral William H. McRaven, the former flag officer who oversaw Neptune Spear, where he specifically referred to Rob O'Neill as "the SEAL that, in fact, shot bin Laden".

[18] Saying "I can't believe I fought for this bullshit", O'Neill again took to Twitter in May 2023 to criticize the Navy's alleged unreadiness to combat China because active-duty sailor and drag performer Joshua Kelley had been a "digital ambassador" for the service in 2022.

[26][27] In December 2023 O'Neill held a small share in the Armed Forces Brewing Company in Norfolk, Virginia, that struggled to receive planning permission.

[28][29] On November 4, 2024, O'Neill was criticized online for his sexually charged reply to a tweet publicizing five young mens' vote for Kamala Harris in the 2024 United States presidential election.