Simple Summary: Aquatic invertebrates are understudied and often overlooked in public aquarium welfare. By determining public opinion on aquatic invertebrate welfare, we can obtain a better picture on whether they are even considered during an aquarium visit. Using TripAdvisor, it was determined that aquatic invertebrates were under-represented in negative welfare comments compared with their vertebrate counterparts. The public were more likely to comment on welfare issues if from the UK or USA. To aid in a better understanding of aquatic welfare by the public, zoo and aquarium associations should help create guidelines for aquatic invertebrates. Guideline creation would help increase the construction of welfare indicators and support welfare tool kits. This would hopefully result in the better consideration of invertebrate welfare and public understanding in public aquaria. Awareness of welfare issues within animal collections is increasing as information becomes more accessible for staff and the public. A knowledge gap remains when considering the welfare of invertebrates, particularly when housed in public aquaria. TripAdvisor comments were analyzed for 485 worldwide aquariums. The public focused on anthropogenic features or charismatic organisms within collections. Invertebrate welfare was only presented in 18% of negative welfare comments compared with the 51% of represented vertebrates and 31% of negative general welfare comments. The UK and USA reported a greater number of perceived invertebrate welfare issues. Greater dissemination of information between aquarists and scientists should be encouraged to drive welfare standards and improve husbandry. In addition, incorporating input from invertebrate aquarists while utilizing welfare toolkits are vital for improving overall standards if we are to have greater representation of invertebrate welfare in public aquaria. [ABSTRACT FROM AUTHOR]