Riitta-Liisa Roponen (née Lassila, born 6 May 1978) is a Finnish cross-country skier who has competed since 1998.

She won a bronze in the 4 × 5 km relay at the 2010 Winter Olympics in Vancouver.

Roponen also won two team sprint medals at the FIS Nordic World Ski Championships with a gold in 2007 (with Virpi Kuitunen) and a silver in 2005 (with Pirjo Manninen).

Roponen's best individual finish at the Winter Olympics is sixth in the 10 km freestyle at Vancouver in 2010.

All results are sourced from the International Ski Federation (FIS).