McDonald will leave fast food chain McDonald's where she is UK chief and president of North West Europe.
The former marketing chief joined the restaurant business in 2006 and has served in her current role since 2010.
Here's what Halfords chairman Dennis Millard had to say:
When the board began the search for a new chief executive we were clear that we were looking for an outstanding business leader, particularly someone who had built and nurtured a culture of customer service and colleague engagement in a consumer facing business. So we are delighted to have recruited Jill, who has a strong track record of heading a large, complex, service-led business with great success. Jill will lead our high-calibre team and further develop Halfords' successful service-based growth strategy. I'm really excited that we have attracted someone of Jill's calibre who will build on what we've achieved over the last few years and we all really look forward to working with her.
And McDonald, also the former head of global marketing for British Airways, said this:
Halfords is a business and brand that resonates with me and the UK public and I am delighted to be joining the company. Halfords has already made significant progress in delivering its service-led growth strategy and I look forward to joining such a strong team to continue to build on that success.
She'll start at Halfords on 1 May.