The 30-year-old socialite - who appears alongside her family in the hit show Keeping Up with the Kardashians as well as starring with sister Kourtney in Kourtney & Kim Take New York - topped the list by US-based website The Daily Beast after earning $6m in 2010.
Former Hills star Lauren Conrad came second, taking home $5m, while Kim's sisters Khloe and Kourtney also made the list after each earning $2.5m.
Kim is said to earn up to $75 000 for a personal appearance and has made a fortune from endorsement deals, which include Skechers sneakers, Kotex tampons, as well as her own range of swimwear, jewellery and perfume.
The Daily Beast's list measured those "who've cashed in on fame versus talent" and they only counted reality TV stars with a show that aired or was in production in 2010.
Other stars to make the list include former Playboy model Kendra Wilkinson, mother-of-eight Kate Gosselin, former Real Housewives star Bethenny Frankel and Audrina Patridge, who is working on her own programme, entitled The Audrina Show, after originally shooting to fame on The Hills.
Highest-paid reality TV stars in 2010 according to The Daily Beast:
1. Kim Kardashian: $6m
2. Lauren Conrad: $5m
3. Bethenny Frankel: $4m
4. Audrina Patridge: $3.5m
5. Kate Gosselin: $3.5m
6. Mike 'The Situation' Sorrentino: $3m
7. Khloe Kardashian: $2.5m
8. Kourtney Kardashian: $2.5m
9. DJ Pauly D: $2m
10. Kendra Wilkinson: $2m