Senior medical research engineer Corey Robinson, who was born in the constituency, will be standing for the regional party in the election triggered by MP Tracy Brabin's election as West Yorkshire metro mayor.
The party will have high hopes for its performance after coming third in the mayoral election with 58,851 votes, beating the Liberal Democrats and Green Party.
According to the Yorkshire Party Mr Robinson has developed tools to improve public health, including being the main design lead on a device that helps to repair damaged tendons in the hand. His hobbies include competing as a cross-codes rugby player, favouring rugby league.
Mr Robinson said: “Many local people feel disenfranchised with mainstream party politics, which is why as the Yorkshire Party we need to show people that we are different; we are fighting for power and decision making to be moved away from Westminster and for it to be closer to those it impacts.
"Most of the people I knew growing up were not politically active, and many did not vote because they perceived that regardless of who you voted for,
nothing would change.
"It is my ambition to use my understanding of the community and my connections there to engage with the Batley and Spen constituents to show that the Yorkshire Party offers a viable alternative.”
Kim Leadbeater, the sister of former MP Jo Cox, is standing for Labour in the by-election and Ryan Stephenson, the chairman of the West Yorkshire Conservatives, is standing for the Tories.
Yorkshire Party Leader, Bob Buxton, said: “Corey is knowledgeable and passionate about local issues. He was born in the constituency, he knows it in-side-out, he understands problems with transport, air pollution and a lack of social housing and starter homes.
"Unlike other parties, our whole membership voted for who our candidate should be. We chose Corey for his professional talents in medicine and engineering and because we believe local knowledge is important.”
The seat was represented by Mrs Cox until she was shot and stabbed by a far-right extremist in June 2016.
Labour is desperate to hold on to the seat following the party's crushing defeat in another "red wall" by-election in Hartlepool earlier this month.
The result triggered a bitter round of recriminations, with the Labour left - marginalised under Sir Keir - gunning for the party leader.
Former shadow home secretary Diane Abbott - a close ally of ex-leader Jeremy Corbyn - has said it could be "curtains" for Sir Keir if they lose again.
No date has been been set for the contest although Labour - which is defending a majority of 3,525 from the 2019 general election - is widely expected to delay until late July.