The collisiion happened just after 2.50pm on Saturday at the roundabout connecting Brompton Road and Quaker Lane.
The cyclist, a local man in his 40s, was pronounced dead at the scene.
Officers investigating the collision are appealing for witnesses to come forward. They are also urging anyone with dashcam or CCTV footage from the moments leading up to it to get in touch.
The cyclist was riding a dark-coloured bike and the lorry was a Scania HGV.
The driver stopped at the scene and spoke to police, but no arrests have been made.
Anyone with information or footage is urged to contact North Yorkshire Police on 101, select option 1 and quote reference 12220012175.