Muhammad Salah Eldin Bahgat Ahmad Helmy (محمد صلاح الدين بهجت أحمد حلمى, IPA: [mæ'ħæmmæd sˤɑˈlɑːħ el-, edˈdiːn ˈbæhɡæt 'æħmæd ˈħelmi]), known as Salah Jaheen (صلاح چاهين [sˤɑˈlɑːħ ʒæˈhiːn]; December 25, 1930 – April 21, 1986) was a leading Egyptian poet, lyricist, playwright and cartoonist.

In fact, the term "shi'r al-ammiya" or "Arabic colloquial poetry" was only coined in 1961 by a group of young poets including Salah Jahin, Abd Al-Rahman Abnudi, Fuad Qaud and Sayyid Higab who called themselves "Jama't Ibn Arus".

In one interview, he said that with the death of Nasser in 1970 and the sudden shift in political orientation he felt increasingly like Hamlet, with Sadat embodying the treacherous Claudius.

In 1963 Jaheen wrote his quatrains or rubaiyat in which he expressed his beliefs, emotions and views of life, existence, good and evil.

His songs include: "Soura" or photo, "ehna elsha'b" or "we are the people", "Khaly elselah sahy" or "oh weapon, be ready", "Ya ahlan belma'arek" or Welcome battles" and "El-mas'oulia" or "Responsibility".

His screenplays included: "Awdat al ibn al dal" or The return of the prodigal son ; directed by Youssef Chahine, "El less wal kilab" (based on the novel The Thief and the Dogs by Naguib Mahfouz), "Shafika we Metwali" or "Shafika and Metwali", "Khally ballak men Zouzou" ("Watch Out for Zouzou") and "Amira Hoby Ana" or Amira My Sweetheart.

Jahin was a witty political cartoonist, where his sketches of everyday life over the course of four decades "made people laugh and cry at the same time.