A family reunion has a problem no other party does: half the guests already know each other well, and the other half are second cousins and new in-laws who've never met. The games that work best are the ones that force mingling across those lines, not the ones that just entertain people who are already comfortable.
Break the ice with a bingo that forces mingling
A Find-a-Relative bingo card, where each square names a trait or fact ("find someone born in a different state," "find someone who shares your middle name"), only gets filled in if guests actually walk around and talk to people they don't know. Hand cards out at the door before anyone settles into their usual corner.
Run a Family Feud about your own family
Send out a short survey a week or two ahead ("what's Grandpa's go-to saying," "who's most likely to be late") and build a Family Feud-style round from the real answers. It's funnier than a generic trivia game because every answer is an inside joke the whole family already half-knows, and a scoreboard gives it the feel of the real thing.
Trivia and a scavenger hunt for the in-between hours
Reunion trivia built from real family facts (with an answer sheet for whoever's hosting, since nobody remembers everything) keeps the older generation engaged, while a scavenger hunt gives kids and teenagers something to do that doesn't involve sitting at a table.
Story cards get the oral history down on paper
Hand out Remember When and Would You Rather cards at tables during the meal. They're low-pressure conversation starters, not performances, and they're often how the best stories of the day actually get told, the ones that would otherwise only come up once someone mentions them first.
A fill-in family tree and name tags solve the "who is that" problem
Name tags that note each person's branch of the family (not just their name) do more work than any icebreaker game. Put a blank family tree poster somewhere central and let people fill in their own branch over the course of the day; by the end, you've got a document the whole family actually helped build.
Running the day
Hand out name tags and bingo cards at check-in, since both work immediately and don't need a crowd. Run the scavenger hunt and story cards through the early afternoon while people eat and settle in, save Family Feud for the main event once most relatives have arrived, and leave the family tree and recipe cards out all day so people can add to them whenever they think of something.
Our Family Reunion Games kit has all of this ready to print: eight games, a Family Feud survey and scoreboard, 32 story cards, name tags, a fill-in family tree and recipe cards, built for everything from a backyard gathering of 10 to a reunion of 100 or more.