Background: Cardiac dysfunction due to systemic lupus erythematosus (SLE) may be subclinical, but those patients are at high risk for developing clinical heart failure. Aim: The aim of this study is to assess the role of speckle tracking echocardiography (STE) in the early detection of systolic dysfunction in SLE patients. Patients and Methods: This was a case–control study. Participants were subdivided into two groups: Group 1 included 50 SLE patients and Group 2 included 50 healthy controls. Clinical evaluation, echocardiography, tissue Doppler, and STE were performed. Results: Global longitudinal strain (GLS) was significantly reduced in SLE group (−18.95 ± 2.02 vs. −21.4 ± 2.1, P < 0.001). However, there was no significant difference in left ventricular ejection fraction between both groups (P = 0.801). There was a significant positive correlation between the disease duration and age (r = 0.480, P < 0.001), pulmonary artery systolic pressure (PASP) (r = 0.628, P < 0.001), and GLS (%) (r = 0.417, P = 0.012). There was also a significant positive correlation between the disease activity index and GLS (%) (r = 0.7, P < 0.001) and PASP (r = 0.522, P < 0.001). Conclusion: SLE group had GLS % lower than the control group, and this was statistically significant, denoting early systolic dysfunction. Longer duration and high SLE activity index significantly affect GLS. GLS is an excellent noninvasive tool for early detection of subclinical left ventricular systolic dysfunction in SLE patients.