"I went back into tough winter training with an open mind on whether or not I would want to compete indoors this year - training has been going well but I feel that my focus really has to be attempting to win another world title in Russia this summer and not the short-term indoor season," Ennis said in a statement on Monday.
Ennis, 27, won the world title in Berlin in 2009 but finished second to Russian Tatyana Chernova in Daegu two years later.
Her first heptathlon is expected to be in Tallinn, Estonia, at the end of June.
