Sirloin Flap vs Tenderloin — What's the Difference?
Quick Answer
Sirloin Flap (sirloin flap) and Tenderloin (beef tenderloin) are not the same cut: Sirloin Flap is sirloin primal (sirloin flap / bottom sirloin flap); Tenderloin is loin primal (psoas major).
Canonical entities: Sirloin Flap · Tenderloin
Side-by-side
| sirloin flap | tenderloin | |
|---|---|---|
| Primal | sirloin | loin |
| Muscle / location | sirloin flap / bottom sirloin flap | psoas major |
| Character | Thin, loose-grained flap from the bottom sirloin; overlaps skirt/flank in some regional breakdowns. | Most tender muscle of the loin; center cuts often sold as filet mignon. |
Key differences
- Different primals: sirloin vs loin.
- Texture and slicing: compare fibrous, grain-heavy cuts vs more tender steak-style muscles based on each cut’s description.
- Retail naming diverges by country—always map through a canonical cut when translating menus or labels.
When to use each
Sirloin Flap
Pick Sirloin Flap when you want its specific marbling/texture profile: Thin, loose-grained flap from the bottom sirloin; overlaps skirt/flank in some regional breakdowns.
Tenderloin
Pick Tenderloin when its primal/muscle traits fit the dish: Most tender muscle of the loin; center cuts often sold as filet mignon.
Sirloin Flap and Tenderloin are different canonical muscles/primals: Sirloin Flap is sirloin (sirloin flap / bottom sirloin flap); Tenderloin is loin (psoas major).
Choose based on tenderness, marbling, grain direction, and how you plan to cook (sear vs braise vs slice thin).
Read the full guides: sirloin flap (what-is) · tenderloin (what-is) · sirloin flap hub · tenderloin hub