Carbon Fibre-Reinforced Composites (CFRCs) offer exceptional strength-to-weight ratios; however, optimising their mechanical performance while managing energy demands in additive manufacturing remains a significant challenge. Guided by Classical Laminate Theory (CLT), this study investigates the influence of fibre orientation and stacking sequence on the tensile behaviour of 3D-printed CFRCs. Test specimens were fabricated using a Markforged Mark Two printer and subjected to uniaxial tensile testing. Configurations featuring 0°/45° orientations alternating every layer demonstrated the highest tensile strength, followed by 0°/90°, while 45°/90° layups demonstrated the weakest performance. The superior performance of the alternating-every-layer sequences is attributed to improved stress distribution and enhanced interlaminar cohesion. Although energy consumption between tested configurations was minimal, a broader comparison of manufacturing methods revealed substantial variations. Resin Transfer Moulding proved the most energy-efficient; Autoclave Curing required significantly higher energy despite yielding superior part quality; and 3D printing, while offering customisation, was constrained by energy intensity and mechanical variability. These findings offer valuable insights for balancing mechanical performance with energy efficiency in CFRC production, contributing to more sustainable composite design strategies.