Objectives: Little is known about the post-operative functional outcomes of severely frail femur fracture patients, with previous studies focusing on complications and mortality. This study investigated patient- or proxy-reported outcomes after femur fracture surgery in older adult patients with severe frailty. Methods: This was a retrospective cross-sectional study of older adult (>70 years) patients with severe frailty (defined by a Comprehensive Geriatric Assessment-based Frailty Index (FI-CGA) ≥ 0.40), who underwent femur fracture surgery at a Level 1 Trauma Center. Patients or their proxy (i.e., close relative) reported mobility, psychosocial, and functional outcomes at least 1-year after surgery. Results: Thirty-seven predominantly female (76%) patients with a median age of 85 years (IQR 79–92), and a median FI-CGA of 0.48 (IQR 0.43–0.54) were included. Eleven patients (30%) regained pre-fracture levels of ambulation, with twenty-six patients (70%) able to walk with or without assistance. The majority of patients (76%) were able to have meaningful conversations. Of the patients, 54% of them experienced no to minimal pain, while 8% still experienced a lot of pain. Functional independence varied, as follows: five patients (14%) could bathe themselves; nine patients (25%) could dress themselves; fourteen patients (39%) could toilet independently; and seventeen patients (47%) transferred out of a (wheel)chair independently. Conclusions: Despite the high risk of mortality and perioperative complications, many of the most severely frail patients with surgically treated femur fractures regain the ability to ambulate and live with a moderate degree of independence. This information can help healthcare providers to better inform these patients and their families of the role of surgical treatment during goals of care discussions.