Jason Allen, aged 39, was due to start trial this week but pleaded guilty to two offences of burglary and robbery.
He has been jailed for five years for both crimes.
In July 2018, Allen targeted the home of an 86-year-old woman in Milnsbridge, Huddersfield.
He broke into her home and stole money before fleeing.
DC Tony Johnson, of Kirklees District CID, said: “We are pleased with the sentence given to Allen today which reflects the fact that he preyed on elderly vulnerable members of the community. He now faces a significant spell behind bars and I hope this provides some comfort to his victims and their families.”