Family support practices and its influence on senior secondary school adolescents’ socioemotional wellbeing in Port Harcourt city, Rivers State was studied. The study adopted the survey research design, with a study population of 8,332 public secondary school students in the 58 public secondary schools Port Harcourt City, Rivers State. The non-proportionate stratified random sampling technique was used to select 550 senior secondary school students for the study (275 males and 275 females). The instrument for data collection was a 65-item questionnaire designed on a four-point scale of Strongly Agree (SA), Agree (A), Strongly Disagree (SD) and Disagree (D) with scores 4, 3, 2, 1 respectively. Data were collected using the direct contact approach and the questionnaire return rate was 100%. Data obtained for this study were analyzed using mean scores and standard deviations. The decision rule was based on the midpoint for the scale of 2.50 Therefore, only mean scores of 2.50 and above were agreed with, while mean scores below 2.50 were regarded as disagreed with. The study revealed that marital instability and roles played by older family members have great impact on the social and emotional development of adolescents in Port Harcourt City, Rivers State. It is therefore recommended that families are sensitized on regular basis on the on the roles of older family members’ in either promoting or undermining adolescent socio-emotional wellbeing. Also, marital instability and spousal conflicts especially to the notice of the children should be discouraged.