Find 37 fun summer birthday party ideas and themes - including pool party and beach themed celebration ideas and fun ideas for everyone - adults, kids, teens, boys, girls, women, and men! From backyard BBQs and pool parties to beach-themed celebrations and Hawaiian luaus, these summer birthday party ideas include cheap decorations and party favors. From a backyard party to an extravagant birthday celebration, you'll find inspiration for water parties, pirate adventures, and glow parties.