Yes, definitely Venice is a very safe city even for solo travelers. There is practically no crime in Venice and you can safely walk even late at night.
It is definitely safer than other important cities in Italy such as Milan, Rome, and Naples. However, like any other touristic place, public transport and crowded areas might be dangerous in terms of thieves. It is recommended not to take too much money with you when you are out and to use a hotel safe for valuables
Please be aware that there are a lot of pickpockets in crowded places, like Saint Marco piazza or on the vaporetto, especially during peak tourist seasons like Summer or Venice Carnival events.