Need recommendations for cruises from Seattle to Alaska. This will be our first time. Thanks

Too bad you aren't considering Vancouver as your departure point - the available options are quite a bit more in terms of both quantity and quality.

Did one a while back on Holland America. Went to Juneau, Glacier Bay, Sitka, Ketchikan, and Victoria I think.
It was fun with some great scenery. Think it was seven days.

Crystal Cruises from Vancouver. Less transit time from there.

We did Princess out of Vancouver last year. Voyage of the Glaciers I think. Included Glacier Bay NP and College Fjord. Then the train to Denali plus days in their lodge.

I'd recommend one that goes to Seward as a one way, that way you can add a land destination. When you go up and back, it cuts out that option.

That being said, that's what we did. Out of Seattle, stops were Juneau, Sitka, Ketchican and Victoria. All four were great.

I'd redo an Alaskan cruise in a heart beat. Enjoyed it much more than Carribbean (but I liked that too)

Best side trip was whale watching. We did it out of Juneau. Also did a float plane trip over glaciers. Glad we did it but wasn't as epic as I was hoping. Still, seeing glaciers from above, however you do it, is pretty cool.

One way cruises will have more stops. For your first time I recommend finding a cruise line that visits Glacier Bay. Princess does a great Alaskan cruise, as does Holland. There are certainly others - it depends what you are looking for. Feel free to email or message me - I can answer any questions you have and many times I can save $$ on cruises (not with Carnival though - I can get the same rate on it).
Note - if you or your companion have had a DUI/DWI or any other felonies, you may be denied boarding even if departing from Seattle. There are steps you can take to get an exemption (possibly)

Did this trip out of Seattle with Holland America. Great cruise through it was an older crowd. 100% recommend Glacier Bay as mentioned above.

We did H.A. out of Seattle and stopped at jenuea, ketch, sitka and victoria. Did a whale watching tour, a salmon hatchery tour, a hike in sitka forest, and just walked around victoria and ate lunch. We had a great time overall.

Get a balcony on this cruise. You don't want to be on the bow with a few hundred other passengers trying to see the glaciers.

We tacked on 2 days beforehand to explore seattle a bit as well.

I have done two Alaska Cruises. Both started in Juneau and ended in Vancouver and were on Royal Caribbean.

First time I went was about 12 years ago (before kids) and then again about 4 years ago (took the kids, probably 8 and 4 at the time). Both times were great. When we first went, the demographic was all old people. So it was a bunch of senior citizens, and then my wife and I in our low 30s. When we went back a few years ago, it completely changed. The cruise was all families and not a lot of old people.

Cant recommend an Alaska cruise enough. As someone mentioned, going one way gets you more land time, but you cant go too wrong with a round trip. Once you figure out your itinerary, post your cities and we might be able to recommend some excursions. The best time to go is late May - early June.