Though your financial advisor is likely not your tax preparer, he is likely in a better position to understand your comprehensive financial and tax situation.
Whereas you might meet with your tax preparer once each year, you are likely in more frequent contact with your financial advisor. Your advisor, having an intimate knowledge of your financial goals and your professional and family ecology, can advise you on important tax decisions in advance, such as things that must be done before the end of the year.
It is advisable that you engage an advisor who is also a CPA, as they are the best qualified to understand important tax issues. Even better, a CPA who is also a Registered Investment Advisor (RIA).
Tax preparers are very appreciate of clients who are organized and who work with a financial advisor throughout the year and will often make use of the advisor when they have important questions that need to be answered properly.