You can watch Miami Marlins vs Seattle Mariners on the same platforms that carry regular-season MLB games for each team, mainly through MLB.TV, the new Mariners.TV in-market service, and TV/streaming partners that carry Mariners or Marlins broadcasts.

Core ways to watch

1. MLB.TV (single game or team)

  • MLB.TV offers out-of-market streaming for both Mariners and Marlins games on most devices (smart TV, mobile, web, streaming sticks).
  • If you are outside both teams’ home TV territories , this is usually the most straightforward legal option for a one-off matchup.
  • You can purchase a full-league, single-team, or sometimes single-game access, depending on the current season’s offerings.

2. Mariners in‑market options

For fans in the Mariners’ home territory (Washington, Oregon, Alaska, parts of Idaho and Montana, plus some nearby regions):

  • Mariners.TV / MLB App
    • New direct-to-consumer Mariners.TV lets you stream all local Mariners games with no local blackouts via MLB’s platforms.
* Works through MLB.com or the MLB App, with season and monthly plans (for example, around 99.99 per season or 19.99 per month in recent announcements, though pricing can change year to year).
  • Cable / satellite / internet TV
    • Mariners games are carried on MLB-produced feeds distributed via select cable/satellite providers, replacing the old ROOT Sports setup.
* Exact channel varies by provider and package, so you’ll need to check your local listings or your provider’s sports package page.

If the Marlins game at the Mariners (or vice versa) is a regular local broadcast, you just tune into the Mariners’ usual regional feed through these options.

3. Marlins in‑market options

For fans in the Marlins’ local territory (South Florida region and designated surrounding market):

  • The Marlins’ in-market streaming page currently indicates more details are “coming soon,” meaning local streaming is handled through partner RSN or MLB arrangements that can shift season to season.
  • Practically, this usually means:
    • Regional sports network on cable/satellite (e.g., your local Marlins channel, depending on the year).
    • In some seasons, authenticated streaming via that network’s app or via MLB/ESPN-integrated platforms.
  • If you live in the Marlins’ territory, a regional sports channel in your cable/streaming live TV bundle is often required for live games.

4. National broadcasts (ESPN, Fox, etc.)

Sometimes Mariners vs Marlins is picked up as a national game :

  • It could air on networks like ESPN, Fox, FS1, or similar. These games might appear on:
    • Live TV streaming services (YouTube TV, Hulu + Live TV, Fubo, DirecTV Stream, etc.) that carry those channels.
* The ESPN App or Fox Sports app with TV provider authentication.
  • When a game is nationally exclusive, local blackouts can apply in MLB.TV or team-specific apps.

5. Live TV streaming services (general approach)

If you want a “one subscription covers it” approach, many fans use:

  • YouTube TV, Hulu + Live TV, Fubo, DirecTV Stream , etc. which may carry:
    • Your local regional sports channel for Mariners or Marlins.
    • National MLB broadcasters like ESPN, Fox, FS1.
  • These services frequently offer free trials, but availability, channel lineups, and RSN carriage change over time.

Quick practical checklist

  1. Check if you’re in a blackout zone
    • If you’re in the Mariners’ territory, prioritize Mariners.TV / MLB App or your local RSN via cable/streaming.
 * If you’re in the Marlins’ territory, you’ll likely need the Marlins’ local RSN via cable/streaming or whatever MLB/partner solution is active this season.
  1. If you’re out-of-market for both teams
    • Use MLB.TV (team or full package) to stream the game live on supported devices.
  1. Check the specific game listing
    • Look up the exact date of the Marlins vs Mariners game on MLB.com or your team’s schedule to see if it’s flagged as:
      • Local broadcast only
      • National TV game (ESPN, Fox, FS1, etc.)
      • Streaming special (e.g., an exclusive digital platform)
  2. Audio/radio backup
    • If video is tough due to blackouts or subscriptions, both teams usually provide radio/audio streams via MLB platforms and local radio apps.

Mini “forum-style” note

A lot of fans end up combining MLB.TV with a short-term live TV streaming trial to catch both local and national games, then canceling once the key series is over.

TL;DR:
Search the exact game date on MLB.com, then:

  • In Mariners territory: use Mariners.TV/MLB App or your cable/streaming package.
  • In Marlins territory: use the Marlins’ regional sports channel or its linked streaming option.
  • Outside both markets: MLB.TV is usually the simplest way to legally stream Marlins vs Mariners.

Information gathered from public forums or data available on the internet and portrayed here.