An eight‐week feeding experiment was conducted to investigate the effects of dietary crystalline methionine (CMet) or oligo‐methionine (OMet) on growth performance and feed utilization of white shrimp, Litopenaeus vannamei. A practical diet was used as control diet. The other four diets replacing 30% and 60% fish meal by plant meal were formulated. To balance the methionine content, 1 g kg⁻¹ CMet (SPP30‐CMet) or OMet (SPP30‐OMet) was added in 30% fish meal replacing diets, and 2 g kg⁻¹ CMet (SPP60‐CMet) or OMet (SPP60‐OMet) was added in 60% fish meal replacing diets. Results showed that methionine source significantly affected growth, body compositions and hepatosomatic indices (HSI) of white shrimp (P < 0.05). Shrimps in SPP60‐CMet treatment showed significantly lower weight gain, body crude protein content and higher HSI than those in the control (P < 0.05). However, no significant difference in these indices was observed between the control and OMet supplemented treatments (P > 0.05). Shrimps in SPP30‐OMet treatment showed significantly higher feed efficiency ratio and protein efficiency ratio than those in SPP30‐CMet treatment (P < 0.05). This study indicated that compared with the CMet, dietary OMet resulted in better growth and feed efficiency of L. vannamei fed with plant protein‐enriched diets.