Best things to do in Milan

The Last Supper and the Duomo were the biggest priorities for me. Nothing else came close.

We have been to Milan twice to visit the awesome work of art by da Vinci, “The Last Supper.” We have enjoyed staying in Milan.

Apply on line for the Duomo elevator to the top of the Duomo. Awesome views and up close look at the amazing architecture. Also make sure it also includes the entrance to the interior of the church.

Ditto Carroll's post although your top five may not be the same as mine.

I also wanted to see the Pinacoteca Ambrosiana which holds the cartoon Raphael drew for his fresco in the Vatican Museum called The School of Athens. They also have Leonardo's Codex Atlanticus which was very cool to see with his mirror writing. There were some other lovely surprises in the not-very-crowded museum.

Many also like to walk thru the Galleria Vittorio Emmanuele which has high end stores and leads thru to the La Scala Opera House.

Do you have lodging yet or do you want suggestions? How many nights will you be there?

https://www.ricksteves.com/europe/italy/milan

In addition to the things mentioned above and Rick's list, I'd point out that Milan has lots of Art Nouveau architecture that would be of interest to at least some architecture buffs.

These haven't been mentioned... Pinacoteca di Brera, San Maurizio al Monastero Maggiore

My best memories are of walking out of the metro and seeing the Duomo gradually emerge, wandering on the Duomo roof, walking through Galleria Vittorio Emmanuele, in that order. I also enjoyed a tour of La Scala and several hours at the Sforzesco Castle and its museums. I wasn't able to book the Last Supper.

The roof of the Duomo, the Brera, and the monumental cemetery. We also really enjoyed the church of San Maurizio al Monastero Maggiore, the old street cars, and walking around the Navigli area.

We were there 2 years ago. We did not do the Last Supper. We did visit the Duomo, the roof, and the museum. We visited Castelo Sforesco, which has a lot of small venues in it. We had sort of an adventure in that there was a strike on one transit form, so we had to improvise, which is the most fun part of travel. We spent an evening in the Naviglio district (canals) with many restaurants and bars. Built 500 years ago by da Vinci.

Besides the well known sites, I agree with the suggestion above to visit San Maurizio al Monastero Maggiore. And for the Best gelato, do not miss Ciacco.

After you enjoy some of the big sights...I would recommend taking the metro to the Navigli canal area and enjoy a day of strolling along the canal, eating etc. it's really a lovely area to take a break from the "city".

We spent two nights and the absolute biggest highlight was the Last Supper. We couldn't organise tickets, but luckily our hotel got them for us.

We also loved the rooftop of the Duomo, having a glass of wine and snacks in the piazza in front of the Duomo, the Castle, and a tour of La Scala.

Make sure to eat the area specialities. We live in Australia where schnitzel is a big thing but nothing has ever come close to the coletta I ate in Milan, along with the Risotto Milanese.

Before you go, read the book Beneath a Scarlet Sky about Pino Lela. It will rock your word and have you look at Milan in a whole new light. (it is about an unsung italian hero in WWII).
If you read it, there are so many sites you would want to see from the book. My husband and I rented bikes and biked all around to the different areas talked about in the book. It was fascinating.

Also, The Last Supper was so much more impactful than I thought it would be. Loved it.
Duomo - great to go to the roof
Train station 21 small museum about WWII - they still have the original box cars and rail ways. One of the most powerful WWII museums I've seen (and we've been to A LOT).
A short drive to lake como for a day trip is great also

If you are a fan of fashion the Armani silos are an amazing museum where you can wander around decades of Armani fashions on custom mannequins. The fashions are not just behind glass you can wander between the mannequins and study the work up close if you want to.

Not for everyone but if it's your thing don't miss out,
=Tod

A bit off the beaten path, but if you are a fan of Wes Anderson and his films, I highly recommend a stop at Fondazione Prada and having a drink / snack at Bar Luce. Anderson designed the cafe himself, and it feels like you are stepping into one of his movies. I've been to Milan a few times and always make a point to stop there. It has a retro 50s/60s vibe and even a "Life Aquatic" themed Zissou pinball machine that you can play. As a film buff, it was one of my top 5 must-sees the first time I visited the city.