Security searches at entrances and on-site sniffer dogs will feature at the five-day event which began on Tuesday and ends on Saturday 18 June.
Extra measures have been taken in the wake of recent terror attacks in Europe and America.
Supt Jim Weems said police will be more visible in and around the site.
"Aside from our duties protecting the Royal party, the public have come to expect a strong security presence at prominent events and occasions. We anticipate the focus remaining firmly on the track but will remain ready to respond if required.
"There isn't currently any threat of terror at the event, but considering the recent stressed environment that we're in - with a huge sporting and crowded event like Ascot - we have to factor that in.
"For the first time this year, we'll have armed officers patrolling paths and the high street so patrols will be more visible to the public."
Up to 280,000 racegoers are due to attend the Berkshire event over the five days, including the Queen who has attended every year since she came to the throne in 1952.
Security at Royal Ascot has been stepped up with over 200 officers - including the armed response - patrolling the event.