In the US, 8.4% of children are diagnosed with asthma by age 18, making asthma one of the most common chronic conditions among children. Additionally, 25% of children experience persistent wheezing by age 6, an indicator of childhood asthma. Both childhood asthma and persistent wheezing may be linked to inflammatory and immune mechanisms, which are associated with inadequate and excessive gestational weight gain. Studies investigating the relationship between gestational weight gain and offspring asthma and wheeze phenotypes are limited by self-reported gestational weight gain, early age at asthma and wheeze assessments, limited adjustment for potential confounders and no trimester-specific evaluations. Therefore, we investigated the association between total and trimester-specific gestational weight gain, offspring asthma and wheeze phenotypes among 2128 mother-child pairs in Project Viva, a prospective cohort study in eastern Massachusetts. Gestational weight gain was abstracted from medical records and self-reported prepregnancy weight, and defined both continuously and using Institute of Medicine guidelines. Offspring asthma was obtained via maternal report at approximately 7 years, while wheeze trajectories were derived via latent class mixed models based on presence of wheeze between 1 and 9 years, inclusively, via maternal report. We investigated the relationship between gestational weight gain, offspring asthma and wheeze phenotypes using multivariable regressions and predicted probabilities, adjusting for important covariates. Most women had excessive gestational weight gain (56%), while 31% had adequate gestational weight gain and 13% had inadequate gestational weight gain. Approximately 18% of children had current mid-childhood asthma, 13% had early transient wheeze and 13% had persistent wheeze. We found a non-linear association between total gestational weight gain and offspring current mid-childhood asthma. Additionally, there was a 36% decreased odds of early transient wheeze among children of mothers with excessive third trimester gestational weight gain (aOR= 0.64; 95% CI: 0.42-0.98). This study adds to the body of literature by incorporating adequate inclusion of confounders and risk factors for adjustment, as well as being the first study to evaluate the association between trimester-specific gestational weight gain, offspring asthma and wheeze phenotypes.