Cambridge Airport (CBG) is primarily a business and general aviation field, historically linked to Marshall Aerospace, rather than a commercial passenger gateway with scheduled airline service, so the honest answer to any cambridge airport lounge search is that there is no public departures lounge here in the way a major hub has one. Private and corporate jet operations, along with aircraft maintenance work, make up most of what happens at this airfield today.
Because Cambridge does not run a scheduled commercial timetable with the premium-cabin and elite-status traffic that supports a public lounge, expect facilities geared toward general aviation, handling agents, small terminal or fixed-base operator space, rather than a Priority Pass or airline-club environment. Private aviation passengers may have access through their operator or handling company, but that is a different arrangement entirely from a public airport lounge.
For travellers in the Cambridge area needing an actual scheduled-flight lounge experience, London Stansted Airport (STN) is the closer commercial option, roughly forty minutes away, with its own mix of airline and third-party lounge access depending on your ticket and card. London Heathrow (LHR), further away but Britain's primary international hub, carries a much larger lounge network across its terminals, airline-run spaces for premium and elite passengers plus extensive Priority Pass and credit-card coverage, for travellers on longer-haul or international routes. Cambridge's own airfield does maintain a small cafe within its general aviation terminal, useful for a coffee between meetings, but it is not comparable to any commercial lounge.
If your journey starts near Cambridge, the practical plan is to treat CBG as a general aviation and business-jet field only, and to route any real commercial lounge question toward Stansted for regional and short-haul European travel or Heathrow for wider international connections, confirming current access details with your airline or card issuer before you fly, since both airports' lounge offerings can change over time.