Can I bring a spouse along for a conference? Is it possible to bring my spouse along for overseas academic conference? (My spouse will not be attending the conference. Airfare and accommodation for my spouse will be paid by us.)

The intention is for my spouse to visit the country and for us to do some sightseeing together during weekends/ off days.

Are there any things to look out for? Has anyone tried this before? 

Thanks for any feedback.
Yes, it is perfectly normal and accepted, at least in all fields I have heard about. Many conferences also allow one to purchase extra tickets for the social program (conference dinner, excursions) for spouses and accompanying persons.

The only possible source of trouble is how to split the hotel bill, since you will (most likely) be sharing a room. Make sure to inquire in advance with the institution that pays for your trip, or at least ask a colleague what the norm is.