The 44-year-old reality star and mother-of-five appeared at Lewes Crown Court on Wednesday 25 May for allegedly breaching a restraining order by sending foul-mouthed texts aimed at Hayler's partner Michelle Penticost.
Price, who was supported by fiance Carl Woods, at the hearing, entered a plea of guilty.
She wore a black coat, black leggings and white boots as she appeared before judge Stephen Mooney. Woods, 33, watched from the public gallery.
She married third husband Kieran Hayler in 2013 and they share and Jett, eight, and Bunny, seven. The couple renewed their marriage vows three times before splitting in 2018.
Price was arrested in January on suspicion of breaking her restraining order against Penticost.
She is said to have sent messages calling her a "c***ing w***e piece of s**t" and a "gutter s**g".
Price had pleaded not guilty at a hearing at Crawley Magistrates Court on 27 April and requested a Crown court trial. But she has now changed her plea to guilty.
She had been handed a five-year restraining order in June 2019 banning her from contacting Penticost directly or indirectly.
The order came after Price hurled a foul-mouthed abusive rant at Penticost during a row in a school playground.
Her case was heard remotely at at Crawley Magistrates' Court under the single justice procedure, which means she will face a fine as well as points on her licence or a further driving ban.
Price — who was declared bankrupt in 2019 — received a suspended sentence in December after she pled guilty to drink-driving in the early hours of 29 September.
She was given a four month suspended sentence and ordered to complete 20 hours of rehab and 100 hours of community service.
Watch: Katie Price has previously entered a plea of not guilty