Wichita A Sedgwick County District jury on Friday found Reginald Johnson guilty of first-degree premeditated murder in the shooting of his wife.
The jury deliberated about six hours before convicting Johnson in the August 2007 death of Amy Whiteman, 36.
Johnson, 38, will be sentenced April 4.
Public defender Ken Newton had asked the jury to consider voluntary manslaughter, which would have indicated Johnson acted violently in "the heat of passion."
Johnson had testified he was angry after learning his wife of 11 years had been seeing another man.
Prosecutors said the way Whiteman died, with four blasts from a 12-gauge, single-action shotgun, showed a deliberate, premeditated act.
Johnson testified he blacked out and doesn't remember shooting her.