Shani Mantras

Shani Beej Mantra:

Om Praam Preem Praum Sham

Shanayishraya Namah

Vyas Vicharita Mantra:

Nilanjana samabhasam

Raviputram yamagrajam

Chaya martanda sambhutam

Tam namami Shaneshwaram

Gayatri:

Om Neelambharaya vidhmahe

Soorya Putraya dhimahi

Tanno sauri prachodayath

Om Sanaischaraya vidhmahe

Sooryaputraya dheemahi

Tanno manda prachodayat

From Brahmanda Purana:

Suryaputhro Deerghadeho Vishaalaakshah

Shivapriyah Mandachaarah

Prasannathmaa peedam harathu me Shanih

Mula Mantra:

Om Sham Shanicharaya Namah 

For other Shani stotras look the tag Shani in my blog