Captain's Cove Seaport—Bridgeport
Smack dab in the middle of the marina on Black Rock Harbor, Captain's Cove Seaport offers a terrific family friendly outing. The casual restaurant offers fish and chips, burgers, and all the usual bar foods, as well as an affordable kids' menu that includes the standard fare (and offers apple slices in place of fries).  On Sunday afternoons, there is often music, and if you'd prefer to wander, the boardwalk is lined with little shops. Fishing charters are available and there's even a sailing school that offers classes for kids beginning at age 9.

Overton's—Norwalk

Photo courtesy of lastcupscilla via Instagram  

Right on the water on Seaview Avenue in East Norwalk, Overton's is a Fairfield County tradition. With it's laid back atmosphere and casual self-serve seating on the deck behind the ordering window, it's also a perfect starter restaurant for families with young children. Overton's is known for its fried seafood (including fried clams), and my kids rave about their hot dogs. Be aware that the seagulls can be a little aggressive with unattended food so don't dawdle too long over those fries! When you've finished eating, stroll up the block to Mr. Frosty's for some dessert—their soft custard and tornado mix-ins are not to be missed!

Sono Seaport Seafood—Norwalk
You can dine inside or out right beside Norwalk Harbor at the quaint Sono Seaport Seafood. Their fried seafood (including whole belly clams) is always a hit, and it's a terrific spot to introduce visitors to the Connecticut-style lobster roll (warm, with butter). The children's menu is extensive, and the staff is accommodating. Note: Sono Seafood is not far from the Maritime Aquarium, but it can be a bit of a walk without a stroller—especially if your kids have already spent some time on their feet. There is generally plenty of parking in the restaurant's (free) lot. 

Sunset Grille—Norwalk
You can't get more nautical than the Sunset Grille, which operates in the Norwalk Cove Marina from late April to October. Most of the tables are outside on the deck (there is a canopied area if you're concerned about shade) where you can enjoy spectacular views of Norwalk Harbor. As you might expect, the menu is seafood-heavy, with a nod to Italian, and there's a reliable children's menu with kids' favorites, such as burgers and fries and buttered noodles.

Rowayton Seafood—Norwalk
This picturesque spot right on the Five Mile River in the seaside town of Rowayton is my favorite special occasion restaurant. Reservations are absolutely required on busy spring and summer weekends, and though they are very accommodating of children (with a dedicated children's menu), it can be a rather expensive outing. For a slightly less expensive, more casual option, head to the Rowayton Seafood Market, right next door, which has a lobster shack vibe (you can order cooked food to eat on the patio as well as buy ingredients to take with you and cook at home). Note: Parking in Rowayton is notoriously tight, and the restaurant offers only a valet option, which can take quite a bit of time (especially when it's crowded). 

Rowayton Market—Norwalk
Not to be confused with the Rowayton Seafood Market, the Rowayton Market is more of a deli, with excellent prepared foods and salads, as well as sandwiches and breakfast foods. You might not guess from the street view, but out back, there's a lovely, covered deck where you can bring the treats you've acquired inside and dine al fresco with a view of the Five Mile River. The market is also conveniently located if you want to grab something to eat before enjoying Shakespeare on the Sound.