I am often asked by people planning their Wills whether it is possible for a beneficiary under their Will to also be named as the executor. This is particularly common in family situations when of course people want to name their own spouses and children as both beneficiary and executor.
In Alberta there is no law that excludes someone from being both beneficiary and executor. This is done all the time, for example where a married couple name each other as their executors and also leave their estates to each other. In cases like that, not only is there no prohibition against the arrangement, but it is clearly the best arrangement that could be made for that particular person's Will. When one person is inheriting the whole estate, having that person act as executor can simplify administrative matters.
There are some situations in which it does not always make sense for the beneficiary and the executor to be the same person. For example, if you are setting up a trust for your son that is intended to ensure that the son doesn't blow all of his money, it doesn't really make sense for the son to be the executor (which also makes him the trustee of his own trust). When the executor is also the trustee of a trust, he or she usually has the power to decide how much of the money in trust is paid to the beneficiary at any given time. It isn't much protection to put the son in charge of deciding how much money he is to receive.
Rather than naming the first person who comes to mind as your executor, put some thought into what an executor under your Will is going to have to do once you have passed away. Once you have an idea what the challenges will be, you can better decide who is equipped to handle those challenges. Remember that if you need a neutral third party to handle a trust, though not necessarily the whole executorship, you can always consider naming a trust company.
There is one restriction that can cause a problem. You cannot allow your beneficiaries to also act as witnesses. Should one of your beneficiaries also be a witness, your Will is still valid, but that beneficiary's gift is invalid. I have seen Wills in which the person had his children act as witnesses to his home-made Will, and tried to leave the estate to those same children. The gifts were invalid, which basically left the man with no Will at all. Fortunately the mistake was discovered on a Will review while the man was still alive and able to correct it.