Baldomero was born on the 23rd of August, 1925, in Tampa, Florida. He grew up in the Ybor City neighborhood of Tampa and was named after his father who had emigrated from Spain. Baldomero went to Hillsboro High School and acceled in basketball and Junior Reserve Officers' Training Corps program. Almost immediately after graduating high school, he enlisted in the US Navy on the 8th of July, 1943.

The following year, Baldomero attended the US Naval Academy as part of an accelerated three year program since World War 2 was still on going. He graduated on the 6th of June, 1947, and was commissioned as a 2nd Lieutenant in the Marine Corps. Baldomero then attended The Basic School at Quantico, Virginia, and in 1948 he was assigned to China where he was a mortar section commander and then a rifle platoon commander. Baldomero then transitioned from China to Camp Pendleton, California, where he was stationed at the beginning of the Korean War. He volunteered to deploy to Korea as an infantry officer and was promoted to 1st Lieutenant on the 16th of June, 1950. Three months later, on the 15th of September, 1950, Baldomero displayed actions that would posthumously earn him the Medal of Honor. The citation reads:

For conspicuous gallantry and intrepidity at the risk of his life above and beyond the call of duty as a Marine platoon commander of Company A, in action against enemy aggressor forces. With his platoon 1st Lt. Lopez was engaged in the reduction of immediate enemy beach defenses after landing with the assault waves. Exposing himself to hostile fire, he moved forward alongside a bunker and prepared to throw a hand grenade into the next pillbox whose fire was pinning down that sector of the beach. Taken under fire by an enemy automatic weapon and hit in the right shoulder and chest as he lifted his arm to throw, he fell backward and dropped the deadly missile. After a moment, he turned and dragged his body forward in an effort to retrieve the grenade and throw it. In critical condition from pain and loss of blood, and unable to grasp the hand grenade firmly enough to hurl it, he chose to sacrifice himself rather than endanger the lives of his men and, with a sweeping motion of his wounded right arm, cradled the grenade under him and absorbed the full impact of the explosion. His exceptional courage, fortitude, and devotion to duty reflect the highest credit upon 1st Lt. Lopez and the U.S. Naval Service. He gallantly gave his life for his country.

The following year, on the 30th of August, 1951, Baldomero's parents received his Medal of Honor from the Secretary of the Navy, Dan Kimball. He was 25 years old when he died and several structures have been named in honor of Baldomero: a state nursing home and school in Seffner, Florida, a Korean War memorial in Tampa, a public swimming pool in West Tempa, a US Navy container ship, a state veteran's nursing home in Land O'Lakes, Florida, all bear his name as well as room number 3021 in the US Naval Academy dormitory is dedicated to him with a bronze plaque with his citation on display. Baldomero Lopez is buried in the Centro Asturiano Memorial Park Cemetery in Tampa, Florida; section 57, lot 1.