Laridae
- Heermann's Gull Larus heermanni Rare/Accidental Near-threatened
- Ring-billed Gull Larus delawarensis
- Herring Gull Larus argentatus
- Bonaparte's Gull Chroicocephalus philadelphia Rare/Accidental
- Laughing Gull Leucophaeus atricilla
- Gray Gull Leucophaeus modestus Rare/Accidental
- Franklin's Gull Leucophaeus pipixcan
- Sabine's Gull Xema sabini
- Swallow-tailed Gull Creagrus furcatus Outlying islands only
- Gull-billed Tern Gelochelidon nilotica
- Caspian Tern Hydroprogne caspia
- Elegant Tern Thalasseus elegans Near-threatened
- Sandwich Tern Thalasseus sandvicensis
- Royal Tern Thalasseus maxima
- Common Tern Sterna hirundo
- Forster's Tern Sterna forsteri Rare/Accidental
- Least Tern Sternula antillarum
- Bridled Tern Onychoprion anaethetus
- Sooty Tern Onychoprion fuscata Rare/Accidental
- Black Tern Chlidonias niger
- Black Noddy Anous minutus Rare/Accidental
- Brown Noddy Anous stolidus
- White Tern Gygis alba Rare/Accidental
- Black Skimmer Rynchops niger
Read more about this topic: List Of Birds Of Costa Rica