For all practical purposes, yes. If you are financing, your lender will require one regardless of what you would prefer — and the choice you actually control is which lawyer, and how early.
There is no rule that a private cash buyer must personally retain counsel. But almost nobody buys that way, and every mortgage lender we deal with requires a lawyer to register their security against title and to give them an opinion that the title is good. So the realistic answer for a financed Calgary purchase is that a lawyer is not optional.
Both sides have their own. Your lawyer acts for you; the seller's acts for the seller.
Your REALTOR® negotiates the deal and manages the conditions. Your lawyer moves ownership. Neither can do the other's job, and the handover between them is where a well-run purchase quietly succeeds.
Retain before your conditions come off, not after. Conveyancing is deadline-driven procedural work, and a firm that closes these constantly will spot an RPR or compliance problem while there is still time to fix it. Ask for an all-in quote including disbursements, ask when they need your funds, and ask what they will need you to bring to signing.
The full week-by-week sequence from firm deal to keys is in our Alberta closing timeline guide.