The characteristics of welding residual stress distribution in high-strength steel for offshore structures were evaluated based on the effect of constraint. It is well known that high-strength steel exhibits a high welding residual stress, and the welding residual stress is a significant factor for evaluating unstable fractures. Test specimens were manufactured by applying different constraint conditions. The constrainted and unconstrainted specimens were welded with the same welding consumables and conditions to evaluate the welding residual stress distribution characteristics. The cutting method was applied to assess the welding residual stresses of both specimens. The results showed that the welding residual stress at the heat-affected zone of the unconstrainted specimen decreased compared with that of the constrainted specimen. However, angular distortion occurred in the unconstrainted specimen instead of reduced welding residual stress.