Objective To investigate the correlation between objective sleep characteristics and suicidal ideation. Methods A total of 128 elderly female patients with depression who were hospitalized at the Anhui Mental Health Centre from February 2019 to December 2021 were selected as study subjects by the convenience sampling method. They were divided into the suicidal ideation group （n=81） and the non-suicidal ideation group （n=47）， according to the score of Item 3 in the Hamilton Depression Scale （HAMD）. The total sleep time， sleep latency， sleep efficiency， rapid eye movement sleep latency （REML）， awakening times， total awakening time， non-rapid eye movement sleep sleep time in different stages （N1， N2， N3）， and rapid eye movement sleep were evaluated by polysomnography. The general information， severity of depressive symptoms， and objective sleep characteristics were compared between the two groups. Binomial Logistic regression was used to analyze The relationship between objective sleep characteristics and suicidal ideation in elderly female patients with depression. Results Univariate analysis results showed that there was a statistically significant difference in occupational category， HAMD score， sleep efficiency， total sleep time， total awakening time， awakening frequency， N1 sleep time， N2 sleep time， N3 sleep time， and REML between the two groups of patients （P ＜ 0.05）. Binomial Logistic regression analysis showed that after controlling for occupational categories and severity of depressive symptoms， sleep efficiency （OR=0.857， 95%CI=0.748-0.983）， total sleep time （OR=0.971， 95%CI=0.947-0.996）， awakening frequency （OR=1.092， 95%CI=1.005-1.188）， N1 sleep time （OR=1.059， 95%CI=1.018-1.101）， and N3 sleep time （OR=0.976， 95%CI=0.956-0.996） are influencing factors for suicidal ideation in elderly female depression patients （P ＜ 0.05）. Conclusions Some of the objective sleep characteristics of elderly female patients with depression， including decreased sleep efficiency， decreased sleep time， increased awakening frequency， prolonged sleep time in N1 phase， and decreased sleep time in N3 phase， make patients more prone to suicidal ideation.