Eric Joering, 39, and 54-year-old Anthony Morelli were killed at a home in a suburb in Columbus, Ohio, around noon on Saturday, police have said.
Choking back tears at a press conference, Westerville police chief Joe Mortbitzer said the officers were "true American heroes" who "gave their lives in defence of others".
"These were two of the best we have. This was their calling, and they did it right," he said.
The pair were responding to a "potential domestic situation" at around noon on Saturday, according to the police.
Trea Horne, a teenager who lives across the street from where the men were shot, said a couple had moved into the home about eight months ago and argued frequently, with police often being called to incidents.
The 17-year-old said he heard five or six shots then saw police cars pulling up to the street on Saturday.
A woman living nearby said police officers were seen nearly dragging firefighters who responded toward the house.
Police chief Morbitzer said the pair were "immediately met with gunfire" when arriving at the scene. Mr Morelli had been on the force for 29 years and Mr Joering for 16 years, he added.
The suspect was wounded and is now in custody after being taken to hospital, police said.
Both President Donald Trump and Ohio governor John Kasich expressed condolences following the incident.