It means the London club's Centre Court will hold almost 9,000 people for the June tournament which marks the start of the grass-court season.
Queen's has also signed a deal with the Lawn Tennis Association to host the championships until 2026.
Tournament director Stephen Farrow said the traditional Wimbledon warm-up event would be "better than ever" in 2017.
"Last year we sold out within 24 hours and enjoyed a 20% increase in hospitality sales, so the demand for an increase in capacity is clear," he added.
Britain's two-time Wimbledon and Olympic champion Andy Murray is the holder and record five-time winner.
Next year's tournament runs from 19 to 25 June.
The Queen's Club will increase its capacity by more than 2,000 seats for the 2017 Aegon Championships.