My daughter (early 20s) and I will be attending a concert in January at the Oakland Arena. I am looking for a hotel that would be a good location. We are flying in to Oakland and not renting a car, but will be using BART. Not sure how late BART runs so not sure if we will be able to use after concert or should we stay within walking distance.

Bart runs usually until 12:30AM and sometimes extends it's operations certain days/events. Check out their routes and schedules at www.bart.gov-You do not want to bw walking around the Oakland arena area period! So I think I would consider an SF hotel. You can use Bart easily from downtown SF.
You could consider a location in Oakland such as Jack London Square-
the Waterfront is nice-but may be more of a walk to/from Bart than you want to
be doing at any late hour. Hope tha helps.
R5

Is it safe to walk from Bart station to Oakland Arena and back?

Look on the Bart sytem map-the Arena/
Coloseium(SP?) IS a Bart stop and quite safe.I have used it for baseball(coloseium) and basketball(arena).The 2 venues are next door to one another.
R5

The BART station in Oakland near the arena is NOT in a GOOD area during the day or night time hours. I have been there to experience this. I would look for other recommendations.

I think BART itself is fine, as is the Arena for the most part, but I wouldn't stay near the Arena. Check out one of the hotels in downtown Oakland near a BART stop. If you're going to a concert at the Arena, you will likely be coming and going with a well-lit crowd. I've done this many times without a problem. Have fun!

The Arena and BART station are in a pretty dicey area - but as tpl says, you will be walking to and from the arena with hundreds of other concert goers and should be safe enough. BUT - that is the least of your worries. None of the hotels/motels near the arean or along Hegenberger are safe or comfortable. With the possible exception of the Hilton which is near the airport and not close to BART, I would not stay in the area. (One of my branch offices that I had to visit every few months is right off Hegenberger and I have stayed in several, know the area VERY well and was robbed once -- but hey, that could happen enywhere)

I usually had a car so preferred to stay on the marina down in San Lenadro or in Jack London Square. But if you want to use BART, stay in SF or very near a BART station in central Oakland, or farther north.

Stay in Berkeley. Take BART to the coliseum. It is safe to walk from BART to the coliseum. There is an elevated walkway from the station to the arena and a lot of people will be doing the same thing so you will have plenty of company. They usually have some security on the bridge area as well for major events. Ball games etc....