Oxidative stress (OS) occurs when antioxidants fail to neutralize an overabundant concentration of reactive oxygen species, resulting in damage to cellular components. This phenomenon is prevalent in neonatal calves, potentially causing disease vulnerability and immune dysfunction. Past studies have shown the benefits of fish and flax oil on calf health and growth due to their omega-3 fatty acids (n-3 FA); these metabolites may mediate inflammation and OS through anti-inflammatory and antioxidant properties. We hypothesized a 60 mL fish and flax oil colostrum supplement would improve indicators of calf health and plasma concentrations of n-3 FA during the first week of life. Sixteen Holstein calves were blocked by sex and birth date and randomly assigned to control (no supplement; Con), or fish and flax oil (FFtrt) supplemented in first colostrum (3 L within 6 h, > 22% on Brix). FFtrt was a 60 mL 1:1 blend of oils with 200 mg α-tocopherol. Blood was sampled on d 1, 2, 4, 7, 14, and 21 after birth for assessment of passive transfer, oxidant status, and FA profile. Health was scored daily. Hip height and body weight were recorded weekly. Data were analyzed with a mixed procedure in SAS 9.4 including treatment, sex, and day as fixed effects and calf and block as random effects. FFTrt did not alter concentration of total protein in blood serum, prevalence of diarrhea, or rate of growth (P > 0.10), but tended to improve nasal scores (P = 0.07). FFtrt increased plasma concentrations of n-3 FA as much as 90% by 1 d of age (P < 0.01). FFtrt decreased oxidant status index (OSi) by 55% by 2 d of age (Con: 73, FFtrt: 32 OSi; P < 0.01) and remained decreased overall in the first week of life (Con: 74, FFtrt: 50 OSi; P < 0.01). OSi and FA concentrations returned to control values by d 14. In conclusion, a colostrum supplement of n-3 FA and α-tocopherol decreased oxidant status and increased plasma n-3 FA concentrations in the first week of life and has the potential to improve health of neonatal calves.