Defence Secretary Penny Mordaunt also attended the celebrations and met serving personnel in the military village in Salisbury's Hudson's Field.
Ms Mordaunt told Forces News that Armed Forces Day is about thanking the military.
"Salisbury has always had an amazing connection to our armed forces," she said.
"I remember visiting Salisbury just a couple of weeks after the [nerve agent attack] last year, and it's done an amazing job as a city - it's really pulled together, all of the services and agencies here, providing that reassurance.
"The public coming in at these events, it gives them their chance to say 'thank you' to our armed forces who stepped in, provided that reassurance, clearly did some really difficult jobs over those weeks and months - it's their chance to say thank you to those people."
Jeremy Hunt thanked the armed forces and reaffirmed his pledge to boost defence spending by £15 billion if he becomes prime minister, while Boris Johnson said it was "an honour" to meet members of the armed forces at a flag-raising ceremony in Ellesmere, Shropshire.
After watching the parade through Salisbury, the chief executive of forces charity SSAFA and former British Army officer Lieutenant General Sir Andrew Gregory said: "Fewer and fewer people in this country have direct contact with somebody who is serving or has served.
"A day like today, where they can see men and women in our military, see some of our veterans, thank them for what they do, celebrate their achievements could not be more important."