Outside of T-Mobile Park, the current name of the Mariner's stadium, and a couple of colleges, almost all Seattle baseball fields are part of the park system managed by the Seattle Parks and Recreations. While a handful of the Seattle Parks baseball fields are available for drop-in play, most require a reservation to use. See below for more information.
Seattle Parks and Recreation manage a number of playfields throughout the city of Seattle, most of which include one or more baseball fields. Thirty baseball fields have synthetic surfaces (entire field or just the outfield), which is nice during the rainy months, and you will find lights on some of the newer baseball fields. Most baseball fields require a paid reservation to use, and while not technically allowed, it's fairly common to see small groups using these fields when not in use. Seattle Parks has designated a small number of baseball fields as drop-in and fee free during certain hours, including Miller, Washington Park, Bobby Morris, Lower Woodland, Montlake, Brighton, Genesee Upper, Georgetown, Van Asselt Elementary, and Walt Hundley.
Gilman Park, the Ballard neighborhood of Seattle, has two baseball fields, one in the northeastern corner and the other in the northwestern corner of the park. Each field has a dirt infield and grass outfield, with a backstop, bleachers and dug-out. The baseball fields at Gilman park are popular with little leagues on the weekend.Gilman Park Baseball Fields
Green Lake Park, in the Green Lake neighborhood of Seattle, features two baseball fields in opposite corners of the Green Lake Playfield, and are located next to the Green Lake Community Center. The fields have backstops and bleachers, and are dirt infield and grass outfield. The fields can be soggy during the winter months, and Green Lake is a favorite resting spot for Canada Geese during certain times of year, so the field may be littered with geese droppings.Green Lake Park Baseball Fields
The Jefferson Park playfield, in the North Beacon Hill neighborhood of Seattle, is a turf field in the Southwestern corner of the park that contains both a soccer field as well as a baseball field. The playfield has lights, and the baseball field has a lined turf infield with bases, turf outfield, backstop, dugout and bleachers.Jefferson Park Baseball Field
Magnolia Playfield, in the Magnolia neighborhood of Seattle, has two basefields in the southeast corner of the park. Each field has a dirt infield and grass outfield, and the fields also sport backstop, bleachers and dugout. The outfields are shared with a soccer field as well.Magnolia Playfield Baseball Field
Ross Park has two baseball fields available. In the Southern corner of the park is the lower baseball field with dirt infield and grass outfield. It has a backstop, dugout, bleachers, as well as a scoreboard. The upper field features a backstop and bleachers with a dirt infield, and grass outfield - note the upper field can often be muddy during the winter and spring. The upper field is not listed on the Seattle Parks and Recreations reservation website, so it can presumably be used for drop in play (lower field does require reservation).Ross Park Baseball Fields
There are a total of five separate baseball fields at the lower section of Woodland Park, located in the Phinney Ridge neighborhood of Seattle. They are all located in the Eastern edge of the park and are accessed off of West Green Lake North St. Playfield #1 features a synthetic infield with grass outfield, dug outs, bleachers, batter/pitchers cage, lights and scoreboard. The field is entirely surrounded by a fence and is not available for drop in play (gates are locked).
Playfields #3 through #6 (Playfield #2 is a soccer field) double as softball and baseball fields. All of them are dirt infields with grass outfields, and they have lights, backstops, dugouts and bleachers. As of 2023, these fields are part of Seattle Park's athletic field drop-in program, allowing free use to small groups during certain hours.