I highly recommend that tourists attend a baseball game in Japan if they have a chance to do so. It's a great atmosphere and cultural experience.
The 2026 season starts on March 27. The schedule was released last week, it is here:
https://npb.jp/games/2026/schedule_04_detail.html
The is is Japanese schedule, most browsers should auto-translate it (Chrome translates it a little better than Safari for me). It takes them a few weeks/months to release an English schedule. The link is to "month 4" (April) you can click the tabs for other months or to switch to calendar view.
Home teams are listed first. (the opposite of how we do it in the USA). So, for example on Friday April 3, the Yomiuri Giants host the DeNA Baystars. Since no other information is given about the location of the game, that means it will be at the Giants' regular home stadium, the Tokyo Dome.
If the game is being played somewhere other than the home team's normal stadium, that is indicated on the schedule. The Hanshin Tigers host the Yokohama DeNA Baystars on April 1-3, but you can see that the games will be held at the Kyocera Dome (a.k.a. Osaka Dome) rather than at the Tigers' usual home stadium, Koshien Stadium.
There are some "countryside" games where the game is played in a neutral site stadium in another city, those are listed as well. For example, on May 12, the Giants host the Carp in the city of Gifu, not at the Tokyo Dome.
Note that where it says "backup day" (like on June 1 and June 8) that means the date is just reserved as a makeup day for those two teams in case it rains (the backup day is right after the interleague series between those two teams). So, more than likely, no game that day.
Game times have not been announced yet, only the dates. But we know that weekday games (Monday-Friday) are generally at 6 p.m. Weekend games generally start at 2 p.m. (sometimes 1 or 1:30). And in the heat of summer, (July-August) weekend games at outdoor stadiums are often scheduled for a 6 p.m. start.
My personal favorite stadium is Yokohama Stadium. It's an outdoor stadium in the heart of downtown Yokohama with great energy. Tourists might also consider a Yakult Swallows game at Meiji Jingu stadium in Shinjuku or a Yomiuri Giants game at the Tokyo Dome in Central Tokyo.
And in the Osaka region, it's popular for tourists to try to go to Koshien Stadium to see the Hanshin Tigers. Those tickets are hard to get though, they often sell out all games within a few days of the tickets going on sale. Seeing the Orix Buffaloes at the Kyocera Dome is also an option.
Mazda Zoom Zoom Stadium in Hiroshima is also an excellent place to watch a game.
Tickets will start going on sale in February or March. Most teams stagger the sales, with tickets for the April/May games going on sale first, and then tickets for the June/July games may go on sale one or two months later, etc.
Good luck. I'm happy to answer any questions, I've been to all the stadiums and a half dozen countryside stadiums too. Here's a thread I posted on Flyertalk reviewing various stadiums, much of the info is outdated now but it will give you an idea of what the stadiums and experience are like:
https://www.flyertalk.com/forum/japan/1791484-jphripjah-reviews-japanese-baseball-stadiums.html
by WoodyForestt