Alan Mason, 45, of Endmoor, Kendal, knew he had the virus for five years when he started a sexual relationship with the woman, from Barrow.
Carlisle Crown Court heard he only told her when she began to feel unwell after contracting the disease herself.
He was jailed for two years and eight months after admitting causing the woman, 39, grievous bodily harm.
After the hearing, Det Con Damian West, of Cumbria Police, said: "This is a unique case for Cumbria and the sentencing imposed highlights the disregard Mason had for his actions.
"Even though the victim has to live with this virus, modern medication means there should be no impact on life expectancy.
"However, the virus has a significant day to day impact on those who have to live with it."
A Cumbrian man who is HIV positive has been jailed for infecting his former partner with the virus.