Background/Objectives: The present study aims to assess the success rate of a CAD/CAM nickel–titanium wire (Memotain®) used as a fixed orthodontic retainer, over a one-year period. Methods: A retrospective study was conducted on 338 CAD/CAM nickel–titanium (Memotain®) fixed retention wires in 205 patients, bonded by a single experienced operator between January 2017 and December 2020. Follow-up visits were scheduled 6 (T1) and 12 months (T2) post-bonding. At each follow-up visit, events (defined as debonding, breakage, retainer loss, or tooth displacement) were classified by tooth, and success or failure of the retainer was determined based on the presence or absence of these events. Results: For the mandibular arch at T1 (6 months), the success rate was 85%, with debonding (n = 46) being the only event observed. At T2 (12 months), the success rate was 77%, with debonding (n = 30), wire breakage (n = 5) and retainer loss (n = 18) having occurred. For the maxillary arch, the overall success rate was 83% at T1 and 78% at T2. Debonding was the most common event observed over the 12-month observation period (n = 29), followed by retainer loss (n = 20) and wire breakage (n = 3). The overall success rates per type of tooth in the upper arch were 86% for the premolars, 96% for the canines, 95% for the lateral incisors and 93% for the central incisors. For the mandibular arch the success rates were 92% for the premolars, 97% for the canines, 96% for the lateral incisors and 94% for the central incisors. Conclusions: CAD/CAM nickel–titanium fixed retainers (Memotain®) demonstrated promising 1-year survival rates in both arches, though long-term multicentre studies are needed to confirm their reliability.