A cyclist has died in a crash involving a semi-trailer at Acacia Ridge in Brisbane's south.

The cyclist collided with the truck near the intersection of Paradise Road and Learoyd Road about 9:40am, Acting Inspector Paul Dalton said.

Police and ambulance officers were on the scene a short time later but the 29-year-old man died from his injuries.

The driver of the truck, a 55-year-old man from Redbank Plains, was not physically injured during the crash.

The Forensic Crash Unit continues to investigate.

Police have been attempting to contact the cyclist's family.