Yorkshire Day, which is held annually on August 1, is now in its 19th year having been inspired by the Yorkshire Society.
It was on August 1 1759 that soldiers from the county's regiments who fought at Minden, Germany, picked white roses from bushes near the battlefields as a tribute to fallen comrades.
The Leeds procession will line up outside the Civic Hall at 11.15am before setting off at 11.30am down Calverley Street and The Headrow. It will arrive at Leeds Cathedral (St Anne's), Cookridge Street, at noon.
Huddersfield's steel pan band, The North Stars, will provide a musical accompaniment. Following a church service the procession will then return to Civic Hall for a reception.
Lord Mayor of Leeds Chris Townsley said: "Being a Yorkshireman born and bred, it is a fantastic honour for me to be Lord Mayor when Leeds hosts Yorkshire Day. It will be a pleasure to share the celebrations of our fantastic country with residents and visitors alike."
Ilkley's town crier will open celebrations in Bradford by reading the official Yorkshire Day declaration followed by a rendition of On Ilka Moor baht'at. The declaration will be made outside the Tourist Information Centre.
The centre is also offering tasters of traditional Yorkshire foods and Yorkshire roses will be on sale, for the official Yorkshire Day charity, the Multiple Sclerosis Society.
Haworth, near Keighley, is playing host to a weekend of family fun and entertainment with events including a vintage tractor rally, a famous Yorkshire people quiz, Punch and Judy and a police dog handling display.
Rotherham Market is getting its fun in first by celebrating Yorkshire Day 24 hours early. A farmers' and crafts market will be in town for the occasion with stalls around Effingham Street.
Other features will include white rose bunting, a Yorkshire Ladies' Barber Shop Choir, and Dinnington Brass Band.
It is Bridlington's turn this year to play host to Yorkshire Day in the East Riding. A giant cake has been donated by Skeltons of Hull and has been mixed by Margaret Chapman, chairman of East Riding of Yorkshire Council.
In York there will be a Made in Yorkshire market in Parliament Street from July 30 to August 1.
The Yorkshire Post is celebrating Yorkshire Day with a week-long series of articles. But we want to know what you think makes Yorkshire so special. Write and tell us about your favourite place in the county, the person you think most embodies the Yorkshire spirit or merely pen a letter of praise. Write to: Yorkshire Day Celebration, Yorkshire Post, Wellington Street, Leeds, LS1 1RF