Background/Objectives: Early recurrence after complete initial transurethral resection of bladder tumor (TUR-BT) may indicate biologically aggressive non-muscle-invasive bladder cancer (NMIBC). This study aimed to identify clinicopathological predictors of ER and its independent impact on progression and survival outcomes. Methods: Clinical data of 335 primary NMIBC patients who underwent TUR-BT between 2012 and 2024 were retrospectively analyzed. Patients with non-primary tumors, incomplete resection, or follow-up <6 months were excluded from the study. Patients were categorized into recurrence-free, early recurrence, and late recurrence groups. Logistic regression was used to identify predictors of early recurrence. Progression-free survival (PFS), cancer-specific survival (CSS), and overall survival (OS) were analyzed using the Kaplan-Meier method and Cox regression. A 36-month landmark analysis was conducted to adjust for heterogeneity in follow-up duration. Results: Early recurrence occurred in 118 patients (35.2%). Independent predictors of early recurrence were tumor size (OR = 1.012, p = 0.038), T1 stage (OR = 2.57, p = 0.004), high-grade pathology (OR = 1.933, p = 0.030), and absence of single-dose intravesical chemotherapy (IVC) (OR = 3.642, p = 0.025). Additionally, adjuvant IVC (OR = 0.279, p = 0.015) and intravesical BCG (OR = 0.427, p = 0.006) independently reduced the risk of early recurrence. Early recurrence independently predicted worse PFS (HR = 6.053), CSS (HR = 2.052), and OS (HR = 1.961) (all p < 0.001). The landmark analysis confirmed these results (all p < 0.05). Conclusions: Early recurrence after initial and complete TUR-BT is an independent predictor of adverse oncological outcomes. Identifying high-risk patients and applying early intravesical therapy may improve outcomes by preventing early recurrence.